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Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
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1

OPTIMAL LOCATION OF ISOLATION VALVES IN WATER  

E-Print Network [OSTI]

CHAPTER 7 OPTIMAL LOCATION OF ISOLATION VALVES IN WATER DISTRIBUTION SYSTEMS: A RELIABILITY systems to serve expanding population centers. Both the adaptation of existing technologies in water supply systems account for the largest cost item in future maintenance budgets. The aging

Mays, Larry W.

2

Michigan: General Motors Optimizes Engine Valve Technology |...  

Energy Savers [EERE]

has resulted in new engine valve technology on the 2014 Chevrolet Impala. EERE's Vehicle Technologies Office supported the research that led to this technical development...

3

Nonlinear System Modeling, Optimal Cam Design, and Advanced System Control for an Electromechanical Engine Valve Drive  

E-Print Network [OSTI]

A cam-based shear force-actuated electromechanical valve drive system offering variable valve timing in internal combustion engines was previously proposed and demonstrated. To transform this concept into a competitive ...

Qiu, Yihui

4

Valve  

DOE Patents [OSTI]

A positive acting valve suitable for operation in a corrosive environment is provided. The valve includes a hollow valve body defining an open-ended bore for receiving two, axially aligned, spaced-apart, cylindrical inserts. One insert, designated the seat insert, terminates inside the valve body in an annular face which lies within plane normal to the axis of the two inserts. An elastomeric O-ring seal is disposed in a groove extending about the annular face. The other insert, designated the wedge insert, terminates inside the valve body in at least two surfaces oppositely inclined with respect to each other and with respect to a plane normal to the axis of the two inserts. An elongated reciprocable gate, movable between the two inserts along a path normal to the axis of the two inserts, has a first flat face portion disposed adjacent and parallel to the annular face of the seat insert. The gate has a second face portion opposite to the first face portion provided with at least two oppositely inclined surfaces for mating with respective inclined surfaces of the wedge insert. An opening is provided through the gate which registers with a flow passage through the two inserts when the valve is open. Interaction of the respective inclined surfaces of the gate and wedge insert act to force the first flat face portion of the gate against the O-ring seal in the seat insert at the limits of gate displacement where it reaches its respective fully open and fully closed positions.

Cho, Nakwon (Knoxville, TN)

1980-01-01T23:59:59.000Z

5

Variable valve timing in a homogenous charge compression ignition engine  

DOE Patents [OSTI]

The present invention relates generally to the field of homogenous charge compression ignition engines, in which fuel is injected when the cylinder piston is relatively close to the bottom dead center position for its compression stroke. The fuel mixes with air in the cylinder during the compression stroke to create a relatively lean homogeneous mixture that preferably ignites when the piston is relatively close to the top dead center position. However, if the ignition event occurs either earlier or later than desired, lowered performance, engine misfire, or even engine damage, can result. The present invention utilizes internal exhaust gas recirculation and/or compression ratio control to control the timing of ignition events and combustion duration in homogeneous charge compression ignition engines. Thus, at least one electro-hydraulic assist actuator is provided that is capable of mechanically engaging at least one cam actuated intake and/or exhaust valve.

Lawrence, Keith E.; Faletti, James J.; Funke, Steven J.; Maloney, Ronald P.

2004-08-03T23:59:59.000Z

6

ANALYSIS OF SAFETY RELIEF VALVE PROOF TEST DATA TO OPTIMIZE LIFECYCLE MAINTENANCE COSTS  

SciTech Connect (OSTI)

Proof test results were analyzed and compared with a proposed life cycle curve or hazard function and the limit of useful life. Relief valve proof testing procedures, statistical modeling, data collection processes, and time-in-service trends are presented. The resulting analysis of test data allows for the estimation of the PFD. Extended maintenance intervals to the limit of useful life as well as methodologies and practices for improving relief valve performance and reliability are discussed. A generic cost-benefit analysis and an expected life cycle cost reduction concludes that $90 million maintenance dollars might be avoided for a population of 3000 valves over 20 years.

Gross, Robert; Harris, Stephen

2007-08-01T23:59:59.000Z

7

ESTIMATION OF EXHAUST MANIFOLD PRESSURE IN TURBOCHARGED GASOLINE ENGINES WITH VARIABLE VALVE TIMING  

E-Print Network [OSTI]

ESTIMATION OF EXHAUST MANIFOLD PRESSURE IN TURBOCHARGED GASOLINE ENGINES WITH VARIABLE VALVE TIMING in turbocharged gasoline engines with variable valve timing requires knowledge of exhaust mani- fold pressure, Pe control systems for gasoline engines rely heavily on feedforward air-fuel ratio (A/F) control to meet

Grizzle, Jessy W.

8

Internal combustion engine with rotary valve assembly having variable intake valve timing  

DOE Patents [OSTI]

An internal combustion engine has rotary valves associated with movable shutters operable to vary the closing of intake air/fuel port sections to obtain peak volumetric efficiency over the entire range of speed of the engine. The shutters are moved automatically by a control mechanism that is responsive to the RPM of the engine. A foot-operated lever associated with the control mechanism is also used to move the shutters between their open and closed positions.

Hansen, Craig N. (Eden Prairie, MN); Cross, Paul C. (Shorewood, MN)

1995-01-01T23:59:59.000Z

9

Closed-loop, variable-valve-timing control of a controlled-auto-ignition engine  

E-Print Network [OSTI]

The objective of this study was to develop a closed-loop controller for use on a Controlled-Auto- Ignition (CAI) / Spark-Ignition (SI) mixed mode engine equipped with a variable-valve-timing (VVT) mechanism. The controller ...

Matthews, Jeffrey A., 1970-

2004-01-01T23:59:59.000Z

10

Towards Real-Time and Memory Efficient Predictions of Valve States in Diesel Engines  

E-Print Network [OSTI]

Towards Real-Time and Memory Efficient Predictions of Valve States in Diesel Engines Philippe Komma T¨ubingen, Germany {philippe.komma, andreas.zell}@uni-tuebingen.de system for a diesel engine

Zell, Andreas

11

Convex Optimization: from Real-Time Embedded  

E-Print Network [OSTI]

Convex Optimization: from Real-Time Embedded to Large-Scale Distributed Stephen Boyd Neal Parikh of Edinburgh, June 25 2014 1 #12;Outline Convex Optimization Real-Time Embedded Optimization Large-Scale Distributed Optimization Summary 2 #12;Outline Convex Optimization Real-Time Embedded Optimization Large

Hall, Julian

12

Depressurization valve  

DOE Patents [OSTI]

A depressurization valve for use in relieving completely the pressure in a simplified boiling water reactor is disclosed. The normally closed and sealed valve is provided with a valve body defining a conduit from an outlet of a manifold from the reactor through a valve seat. A closing valve disk is configured for fitting to the valve seat to normally close the valve. The seat below the disk is provided with a radially extending annulus extending a short distance into the aperture defined by the seat. The disk is correspondingly provided with a longitudinally extending annulus that extends downwardly through the aperture defined by the seat towards the high pressure side of the valve body. A ring shaped membrane is endlessly welded to the seat annulus and to the disk annulus. The membrane is conformed over the confronted surface of the seat and disk in a C-sectioned configuration to seal the depressurization valve against the possibility of weeping. The disk is held to the closed position by an elongate stem extending away from the high pressure side of the valve body. The stem has a flange configured integrally to the stem for bias by two springs. The first spring acts from a portion of the housing overlying the disk on the stem flange adjacent the disk. This spring urges the stem and attached disk away from the seat and thus will cause the valve to open at any pressure. A second spring-preferably of the Belleville variety-acts on a latch plate surrounding and freely moving relative to the end of the stem. This second spring overcomes the bias of the first spring and any pressure acting upon the disk. This Belleville spring maintains through its spring force the valve in the closed position. At the same time, the latch plate with its freedom of movement relative to the stem allows the stem to thermally expand during valve temperature excursion.

Skoda, G.I.

1989-03-28T23:59:59.000Z

13

Motion planning for experimental air path control of a variable-valve-timing spark ignition engine  

E-Print Network [OSTI]

to driveability problems) and on the fuel/air ratio (FAR) (leading to pollution peaks). To compensateMotion planning for experimental air path control of a variable-valve-timing spark ignition engine Syste´mes, Mines-ParisTech 60, bd St Michel, 75272 Paris, France a r t i c l e i n f o Article history

14

Combustion, Control, and Fuel Effects in a Spark Assisted HCCI Engine Equipped with Variable Valve Timing  

SciTech Connect (OSTI)

Widespread implementation of homogeneous charge compression ignition (HCCI) engines is presently hindered by stability, control, and load range issues. Although the operable HCCI speed/load range is expanding, it is likely that the initial HCCI engines will rely on conventional combustion for part of the operating cycle. In the present study, we have investigated the role of fuel properties and chemistry on the operation of a spark-assisted gasoline HCCI engine. The engine employed is a single cylinder, 500 cc, port fuel injected research engine, operating near lambda = 1.0 and equipped with hydraulic variable valve actuation. HCCI is initiated by early exhaust valve closing to retain exhaust in the cylinder, thereby increasing the cylinder gas temperature. This is also referred to as a 'negative overlap' strategy. A total of 10 custom blended gasolines and three different batches of indolene from two suppliers were run at 5 speed-load combinations and performance was characterized by timing sweeps. Within the quality of the data set, we can say the all fuels provided equivalent combustion and performance characteristics when compared at the same combustion phasing. The fuels did, however, require different degrees of retained exhaust as measured by exhaust valve closing angle to achieve the same combustion phasing. Fuels with higher octane sensitivity were found to ignite more easily or more quickly and to burn more quickly than fuels with lower octane sensitivity. This is an expected result since the engine is naturally aspirated and operates with high compression temperatures due to the high retained exhaust fraction and recompression.

Bunting, Bruce G [ORNL

2006-01-01T23:59:59.000Z

15

Safety valve  

DOE Patents [OSTI]

The safety valve contains a resilient gland to be held between a valve seat and a valve member and is secured to the valve member by a sleeve surrounding the end of the valve member adjacent to the valve seat. The sleeve is movable relative to the valve member through a limited axial distance and a gap exists between said valve member and said sleeve.

Bergman, Ulf C. (Malmoe, SE)

1984-01-01T23:59:59.000Z

16

Reducing pressure loss of large diameter check valves  

SciTech Connect (OSTI)

Transcend Inc., a consulting firm that specializes in the use of computer simulation to optimize existing equipment and system designs, was approached by Mannesmann Demag AG, Moenchengladbach, Germany to optimize the design of its DRV-B check valve. In one of the first applications of Computational Fluid Dynamics (CFD) technology to valve design, the pressure loss coefficient (K) of the DRV-B valve was lowered to 0.40--0.50 for valve sizes NPS48--NPS12, the lowest possible level for this type of valve. The flow efficiency is three times better than that of the earlier design. As a result, the optimized Mannesmann Demag DRV-B check valve provides a dramatic reduction in operating cost, particularly in transmission service where natural gas is transported over long distances. The reduced pressure loss saves compressor fuel cost. For the optimized valve, the incremental compressor fuel cost is reduced to 1.5-times the capital cost of the valve calculated over a 20-year Life Cycle Cost (LCC) period.

NONE

1997-09-01T23:59:59.000Z

17

System for detecting operating errors in a variable valve timing engine using pressure sensors  

DOE Patents [OSTI]

A method and control module includes a pressure sensor data comparison module that compares measured pressure volume signal segments to ideal pressure volume segments. A valve actuation hardware remedy module performs a hardware remedy in response to comparing the measured pressure volume signal segments to the ideal pressure volume segments when a valve actuation hardware failure is detected.

Wiles, Matthew A.; Marriot, Craig D

2013-07-02T23:59:59.000Z

18

E-Print Network 3.0 - adjustable gravitational valves Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

with a discussion of control valve calibration, optimization of control constants... valve recovery coefficient CG control valve gas sizing coefficient cV specific heat at...

19

IEEE TRANSACTIONS ON CONTROL SYSTEMS TECHNOLOGY, VOL. 15, NO. 6, NOVEMBER 2007 1065 Robust Optimal Design of Unstable Valves  

E-Print Network [OSTI]

and outer radii of the valve chamber; and 3) the nonmetering orifice momentum flux coefficient which Design of Unstable Valves QingHui Yuan, Member, IEEE, and Perry Y. Li, Member, IEEE Abstract--This paper of electrohydraulic valves. Currently, limitations of solenoid actua- tors have prevented single stage

Li, Perry Y.

20

Mesofluidic two stage digital valve  

DOE Patents [OSTI]

A mesofluidic scale digital valve system includes a first mesofluidic scale valve having a valve body including a bore, wherein the valve body is configured to cooperate with a solenoid disposed substantially adjacent to the valve body to translate a poppet carried within the bore. The mesofluidic scale digital valve system also includes a second mesofluidic scale valve disposed substantially perpendicular to the first mesofluidic scale valve. The mesofluidic scale digital valve system further includes a control element in communication with the solenoid, wherein the control element is configured to maintain the solenoid in an energized state for a fixed period of time to provide a desired flow rate through an orifice of the second mesofluidic valve.

Jansen, John F; Love, Lonnie J; Lind, Randall F; Richardson, Bradley S

2013-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Real-Time Optimization Strategies for Building Systems  

E-Print Network [OSTI]

Jul 2, 2011 ... Abstract: We propose real-time optimization strategies for energy ... proactive, optimization, real-time, electricity markets, energy management.

Victor Zavala

2011-07-02T23:59:59.000Z

22

An electromechanical valve drive incorporating a nonlinear mechanical transformer  

E-Print Network [OSTI]

In traditional internal combustion engines, a camshaft acts on the valve stems to open and close the valves. Valve timing is fixed relative to piston position. On the other hand, if a valve is flexibly controlled by a ...

Chang, Woo Sok, 1964-

2003-01-01T23:59:59.000Z

23

Time-optimal Control of Spin Systems  

E-Print Network [OSTI]

The paper discusses various aspects of time-optimal control of quantum spin systems, modelled as right-invariant systems on a compact Lie group G. The main results are the reduction of such a system to an equivalent system on a homogeneous space G/H, and the explicit determination of optimal trajectories on G/H in the case where G/H is a Riemannian symmetric space. These results are mainly obtained by using methods from Lie theory and geometric control.

Jan Swoboda

2006-01-19T23:59:59.000Z

24

ESTIMATED SIL LEVELS AND RISK COMPARISONS FOR RELIEF VALVES AS A FUNCTION OF TIME-IN-SERVICE  

SciTech Connect (OSTI)

Risk-based inspection methods enable estimation of the probability of spring-operated relief valves failing on demand at the United States Department of Energy's Savannah River Site (SRS) in Aiken, South Carolina. The paper illustrates an approach based on application of the Frechet and Weibull distributions to SRS and Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD) proof test results. The methodology enables the estimation of ANSI/ISA-84.00.01 Safety Integrity Levels (SILs) as well as the potential change in SIL level due to modification of the maintenance schedule. Current SRS practices are reviewed and recommendations are made for extending inspection intervals. The paper compares risk-based inspection with specific SILs as maintenance intervals are adjusted. Groups of valves are identified in which maintenance times can be extended as well as different groups in which an increased safety margin may be needed.

Harris, S.

2012-03-26T23:59:59.000Z

25

Optimal Design of a High-Speed On/Off Valve for a Hydraulic Hybrid Vehicle Application  

E-Print Network [OSTI]

Coefficient 0.6 same none eq Fluid Bulk Modulus 3.7 x 108 1.2 x 109 Pa Pc Check Valve Cracking Pressure 3.2 NOptimal Design of a High-Speed On/Off Valve for a Hydraulic Hybrid Vehicle Application Michael of Minnesota, Minneapolis, MN, USA ABSTRACT Control of hydraulic systems using high-speed on/off valves has

Li, Perry Y.

26

Check valve  

DOE Patents [OSTI]

A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion.

Upton, Hubert Allen (Morgan Hill, CA); Garcia, Pablo (Stanford, CA)

1999-08-24T23:59:59.000Z

27

Check valve  

DOE Patents [OSTI]

A check valve for use in a GDCS of a nuclear reactor and having a motor driven disk including a rotatable armature for rotating the check valve disk over its entire range of motion is described. In one embodiment, the check valve includes a valve body having a coolant flow channel extending therethrough. The coolant flow channel includes an inlet end and an outlet end. A valve body seat is located on an inner surface of the valve body. The check valve further includes a disk assembly, sometimes referred to as the motor driven disc, having a counterweight and a disk shaped valve. The disk valve includes a disk base having a seat for seating with the valve body seat. The disk assembly further includes a first hinge pin member which extends at least partially through the disk assembly and is engaged to the disk. The disk valve is rotatable relative to the first hinge pin member. The check valve also includes a motor having a stator frame with a stator bore therein. An armature is rotatably positioned within the stator bore and the armature is coupled to the disk valve to cause the disk valve to rotate about its full range of motion. 5 figs.

Upton, H.A.; Garcia, P.

1999-08-24T23:59:59.000Z

28

Baton Rouge Complex Steam Real Time Optimization  

E-Print Network [OSTI]

Baton Rouge Complex Steam Real Time Optimization IETC 2014 New Orleans, Louisiana Tope Iyun ExxonMobil Chemical Company May 22, 2014 ESL-IE-14-05-32 Proceedings of the Thrity-Sixth Industrial Energy Technology Conference New Orleans, LA. May 20... were generated by or on behalf of ExxonMobil Chemical Company. Legal Disclosures 2014 ExxonMobil. To the extent the user is entitled to disclose and distribute this document, the user may forward, distribute, and/or photocopy this copyrighted...

Iyun, T.

2014-01-01T23:59:59.000Z

29

Heart Valve Lesson Plan Biomedical Engineering  

E-Print Network [OSTI]

Heart Valve Lesson Plan Biomedical Engineering Objective · Introduce students to biomedical Learning Outcomes · Students will understand the role and function of heart valves. · Students will learn does a heart valve work? · Why do we need to replace heart valves? Time Required (Itemized) · Lecture

Provancher, William

30

Optimization of Air Conditioning Cycling  

E-Print Network [OSTI]

on a 3-ton residential air conditioner are then presented to intuitively understand the effect of expansion valve and evaporator fan cycling in a real system. A real time optimization method is explored and the feasibility, recommendations for a...

Seshadri, Swarooph

2012-10-19T23:59:59.000Z

31

Time-optimal navigation through quantum wind  

E-Print Network [OSTI]

The quantum navigation problem of finding the time-optimal control Hamiltonian that transports a given initial state to a target state through quantum wind, that is, under the influence of external fields, is analysed. By lifting the problem from the state space to the space of unitary gates realising the required task, we are able to deduce the form of the solution to the problem by deriving a universal quantum speed limit. The expression thus obtained indicates that further simplifications of this apparently difficult problem are possible if we switch to the interaction picture of quantum mechanics. A complete solution to the navigation problem for an arbitrary quantum system is then obtained, and the behaviour of the solution is illustrated in the case of a two-level system.

Dorje C. Brody; Gary W. Gibbons; David M. Meier

2014-11-17T23:59:59.000Z

32

Time-optimal navigation through quantum wind  

E-Print Network [OSTI]

The quantum navigation problem of finding the time-optimal control Hamiltonian that transports a given initial state to a target state through quantum wind, that is, under the influence of external fields or potentials, is analysed. By lifting the problem from the state space to the space of unitary gates realising the required task, we are able to deduce the form of the solution to the problem by deriving a universal quantum speed limit. The expression thus obtained indicates that further simplifications of this apparently difficult problem are possible if we switch to the interaction picture of quantum mechanics. A complete solution to the navigation problem for an arbitrary quantum system is then obtained, and the behaviour of the solution is illustrated in the case of a two-level system.

Dorje C. Brody; Gary W. Gibbons; David M. Meier

2015-02-19T23:59:59.000Z

33

Fast acting multiple element valve  

DOE Patents [OSTI]

A plurality of slide valve elements having plural axial-spaced annular parts and an internal slide are inserted into a bulkhead in a fluid conduit from a downstream side of the bulkhead, locked in place by a bayonet coupling and set screw, and project through the bulkhead into the upstream conduit. Pneumatic lines connecting the slide valve element actuator to pilot valves are brought out the throat of the valve element to the downstream side. Pilot valves are radially spaced around the exterior of the valve to permit the pneumatic lines to be made identical, thereby to minimize adverse timing tolerances in operation due to pressure variations. Ring manifolds surround the valve adjacent respective pilot valve arrangements to further reduce adverse timing tolerances due to pressure variations, the manifolds being directly connected to the respective pilot valves. Position sensors are provided the valve element slides to signal the precise time at which a slide reaches or passes through a particular point in its stroke to initiate a calibrated timing function.

Yang, Jefferson Y. S. (Orange, CA); Wada, James M. (Torrance, CA)

1991-01-01T23:59:59.000Z

34

Run-time optimization of adaptive irregular applications  

E-Print Network [OSTI]

adaptive irregular applications for parallel execution, a common observation is that the effectiveness of the optimizing transformations depends on programs' input data and their dynamic phases. This dissertation presents a set of run-time optimization...

Yu, Hao

2004-11-15T23:59:59.000Z

35

Repsol Cartagena Utilities Real Time Optimization -- A Success Story  

E-Print Network [OSTI]

Repsol Cartagena Utilities Real Time Optimization - A Success Story Mike Piccolo and Steve Shyr, Honeywell, and TBD, Repsol, Spain In 1998 Honeywell Hi-Spec Solutions successfully implemented a Utilities Optimization system at Repsol' s Cartagena...

Piccolo, M.; Shyr, S.

36

GENETIC ALGORITHMS APPLIED TO REAL TIME MULTIOBJECTIVE OPTIMIZATION PROBLEMS  

E-Print Network [OSTI]

of searching for multiple solutions concurrently in a single run. Transforming this multiobjective optimizationGENETIC ALGORITHMS APPLIED TO REAL TIME MULTIOBJECTIVE OPTIMIZATION PROBLEMS Z. BINGUL, A. S@harpo.tnstate.edu ABSTRACT Genetic algorithms are often well suited for multiobjective optimization problems. In this work

Coello, Carlos A. Coello

37

Real-Time Optimization Strategies for Building Systems  

E-Print Network [OSTI]

Our analysis indicates that it is possible to obtain energy savings of more ... building-wide, proactive, optimization, real-time, electricity markets, energy man-.

2011-09-02T23:59:59.000Z

38

Signal Timing Optimization to Improve Air Quality  

E-Print Network [OSTI]

the gap that the research on signal optimization at intersections lags behind the development of emissions models. The methodology development includes four levels: the vehicle level, the movement level, the intersection level, and the arterial level...

Lv, Jinpeng 1983-

2012-12-11T23:59:59.000Z

39

Nuclear radiation actuated valve  

DOE Patents [OSTI]

A nuclear radiation actuated valve for a nuclear reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

Christiansen, David W. (Kennewick, WA); Schively, Dixon P. (Richland, WA)

1985-01-01T23:59:59.000Z

40

Optimization of time-based rates in forward energy markets  

E-Print Network [OSTI]

This paper presents a new two-step design approach of Time-Based Rate (TBR) programs for markets with a high penetration of variable energy sources such as wind power. First, an optimal market time horizon must be determined ...

Wang, J.

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Optimizing Marshalling by Run-Time Program Generation  

E-Print Network [OSTI]

Optimizing Marshalling by Run-Time Program Generation Baris Aktemur1 , Joel Jones2 , Samuel Kamin1. Saving the internal data of an application in an external form is called marshalling. A generic marshaller is difficult to optimize because the format of the data that will be marshalled is unknown

Kamin, Sam

42

Piezoelectric valve  

DOE Patents [OSTI]

A motorized valve has a housing having an inlet and an outlet to be connected to a pipeline, a saddle connected with the housing, a turn plug having a rod, the turn plug cooperating with the saddle, and a drive for turning the valve body and formed as a piezoelectric drive, the piezoelectric drive including a piezoelectric generator of radially directed standing acoustic waves, which is connected with the housing and is connectable with a pulse current source, and a rotor operatively connected with the piezoelectric generator and kinematically connected with the rod of the turn plug so as to turn the turn plug when the rotor is actuated by the piezoelectric generator.

Petrenko, Serhiy Fedorovich

2013-01-15T23:59:59.000Z

43

Thermostatic Radiator Valve Evaluation  

SciTech Connect (OSTI)

A large stock of multifamily buildings in the Northeast and Midwest are heated by steam distribution systems. Losses from these systems are typically high and a significant number of apartments are overheated much of the time. Thermostatically controlled radiator valves (TRVs) are one potential strategy to combat this problem, but have not been widely accepted by the residential retrofit market.

Dentz, Jordan [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States); Ansanelli, Eric [Advanced Residential Integrated Energy Solutions Collaborative, New York, NY (United States)

2015-01-01T23:59:59.000Z

44

Combustion Phasing Model for Control of a Gasoline-Ethanol Fueled SI Engine with Variable Valve Timing  

E-Print Network [OSTI]

Combustion Phasing Model for Control of a Gasoline-Ethanol Fueled SI Engine with Variable Valve engine efficiency. Fuel-flexible engines permit the increased use of ethanol-gasoline blends. Ethanol points across the engine operating range for four blends of gasoline and ethanol. I. INTRODUCTION Fuel

45

Force measuring valve assemblies, systems including such valve assemblies and related methods  

DOE Patents [OSTI]

Methods of evaluating a fluid condition may include stroking a valve member and measuring a force acting on the valve member during the stroke. Methods of evaluating a fluid condition may include measuring a force acting on a valve member in the presence of fluid flow over a period of time and evaluating at least one of the frequency of changes in the measured force over the period of time and the magnitude of the changes in the measured force over the period of time to identify the presence of an anomaly in a fluid flow and, optionally, its estimated location. Methods of evaluating a valve condition may include directing a fluid flow through a valve while stroking a valve member, measuring a force acting on the valve member during the stroke, and comparing the measured force to a reference force. Valve assemblies and related systems are also disclosed.

DeWall, Kevin George (Pocatello, ID); Garcia, Humberto Enrique (Idaho Falls, ID); McKellar, Michael George (Idaho Falls, ID)

2012-04-17T23:59:59.000Z

46

Artificial Heart Valve Design  

E-Print Network [OSTI]

Artificial Heart Valve Design Your Chance to be a Biomedical Engineer #12;Circulatory System Video #12;What is a Heart Valve? · Heart Valve Video #12;#12;What Does a Heart Valve Do? · Maintain the one direction flow of blood through the heart · Heart valves allow blood to flow through in a forward direction

Provancher, William

47

Optimal Time-Trial Bicycle Racing with Headwinds and Tailwinds  

E-Print Network [OSTI]

Many time-trial and triathlon bicycle races take place on relatively flat, closed-circuit courses. In the absence of hills, riding-speed is limited almost solely by aerodynamic drag; consequently, winds can have a big effect on elapsed times. I analyze the special case of a straight out-and-back race in a steady wind, assuming the rider has a given total amount of energy to expend and can choose only two speeds - the aided speed with tailwind and the hindered speed into headwind. In this ideal circumstance the problem of choosing optimal riding speeds reduces to a constrained nonlinear optimization that can be solved with elementary calculus. My analysis reveals a practical rule of thumb that can be used more generally to choose optimal riding speeds for time-trial racing on closed-circuit courses in the presence of headwinds and tailwinds.

Anton, A Brad

2013-01-01T23:59:59.000Z

48

Valve for controlling solids flow  

DOE Patents [OSTI]

A fluidized solids control valve is disclosed that is particularly well adapted for use with a flow of coal or char that includes both large particles and fines. The particles may or may not be fluidized at various times during the operation. The valve includes a tubular body that terminates in a valve seat covered by a normally closed closure plate. The valve body at the seat and the closure plate is provided with aligned longitudinal slots that receive a pivotally supported key plate. The key plate is positionable by an operator in inserted, intermediate and retracted positions respecting the longitudinal slot in the valve body. The key plate normally closes the slot within the closure plate but is shaped and aligned obliquely to the longitudinal slot within the valve body to provide progressively increasing slot openings between the inserted and retracted positions. Transfer members are provided between the operator, key plate and closure plate to move the closure plate into an open position only when the key plate is retracted from the longitudinal slot within the valve body.

Feldman, David K. (Fairlawn, NJ)

1980-01-01T23:59:59.000Z

49

Optimizing Matlab through Just-In-Time Specialization  

E-Print Network [OSTI]

Optimizing Matlab through Just-In-Time Specialization Maxime Chevalier-Boisvert, Laurie Hendren,hendren,clump}@cs.mcgill.ca Abstract. Scientists are increasingly using dynamic programming lan- guages like Matlab for prototyping and implementation. Effectively compiling Matlab raises many challenges due to the dynamic and com- plex nature

Verbrugge, Clark

50

Optimizing Matlab through JustInTime Specialization #  

E-Print Network [OSTI]

Optimizing Matlab through Just­In­Time Specialization # Maxime Chevalier­Boisvert, Laurie Hendren,hendren,clump}@cs.mcgill.ca Abstract. Scientists are increasingly using dynamic programming lan­ guages like Matlab for prototyping and implementation. E#ectively compiling Matlab raises many challenges due to the dynamic and com­ plex nature

51

Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems  

DOE Patents [OSTI]

Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

Meisner, Gregory P

2013-10-08T23:59:59.000Z

52

Remote actuated valve implant  

SciTech Connect (OSTI)

Valve implant systems positionable within a flow passage, the systems having an inlet, an outlet, and a remotely activatable valve between the inlet and outlet, with the valves being operable to provide intermittent occlusion of the flow path. A remote field is applied to provide thermal or magnetic activation of the valves.

McKnight, Timothy E; Johnson, Anthony; Moise, Jr., Kenneth J; Ericson, Milton Nance; Baba, Justin S; Wilgen, John B; Evans, III, Boyd McCutchen

2014-02-25T23:59:59.000Z

53

Vacuum breaker valve assembly  

DOE Patents [OSTI]

Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening. 1 fig.

Thompson, J.L.; Upton, H.A.

1999-04-27T23:59:59.000Z

54

Vacuum breaker valve assembly  

DOE Patents [OSTI]

Breaker valve assemblies for a simplified boiling water nuclear reactor are described. The breaker valve assembly, in one form, includes a valve body and a breaker valve. The valve body includes an interior chamber, and an inlet passage extends from the chamber and through an inlet opening to facilitate transporting particles from outside of the valve body to the interior chamber. The breaker valve is positioned in the chamber and is configured to substantially seal the inlet opening. Particularly, the breaker valve includes a disk which is sized to cover the inlet opening. The disk is movably coupled to the valve body and is configured to move substantially concentrically with respect to the valve opening between a first position, where the disk completely covers the inlet opening, and a second position, where the disk does not completely cover the inlet opening.

Thompson, Jeffrey L. (San Jose, CA); Upton, Hubert Allen (Morgan Hill, CA)

1999-04-27T23:59:59.000Z

55

Valve for fluid control  

DOE Patents [OSTI]

A valve for controlling fluid flows. This valve, which includes both an actuation device and a valve body provides: the ability to incorporate both the actuation device and valve into a unitary structure that can be placed onto a microchip, the ability to generate higher actuation pressures and thus control higher fluid pressures than conventional microvalves, and a device that draws only microwatts of power. An electrokinetic pump that converts electric potential to hydraulic force is used to operate, or actuate, the valve.

Oborny, Michael C. (Albuquerque, NM); Paul, Phillip H. (Livermore, CA); Hencken, Kenneth R. (Pleasanton, CA); Frye-Mason, Gregory C. (Cedar Crest, NM); Manginell, Ronald P. (Albuquerque, NM)

2001-01-01T23:59:59.000Z

56

E85 Optimized Engine  

Broader source: Energy.gov (indexed) [DOE]

Optimized Air System Layout Engine 5 8 7 3 1 2 4 MAP EGR Cooler Charge Air Cooler LH Turbo RH Turbo Throttle EGR Valve AirWater Heat Exchangers Wastegate Wastegate Surge valve...

57

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network [OSTI]

the optimization of cogeneration dispatch in a deregulatedcomprised of on-site cogeneration of heat and electricity,of optimal control to a cogeneration system over current,

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

58

Dynamics and real-time optimal control of satellite attitude and satellite formation systems  

E-Print Network [OSTI]

In this dissertation the solutions of the dynamics and real-time optimal control of magnetic attitude control and formation flying systems are presented. In magnetic attitude control, magnetic actuators for the time-optimal rest-to-rest maneuver...

Yan, Hui

2006-10-30T23:59:59.000Z

59

Overflow control valve  

DOE Patents [OSTI]

An overflow control valve for use in a liquid sodium coolant pump tank which valve can be extended to create a seal with the pump tank wall or retracted to break the seal thereby accommodating valve removal. An actuating shaft which controls valve disc position also has cams which bear on roller surfaces to force retraction of a sliding cylinder against spring tension to retract the cylinder from sealing contact with the pump tank.

Hundal, Rolv (Hempfield, PA); Kessinger, Boyd A. (Murrysville, PA); Parlak, Edward A. (North Huntingdon, PA)

1984-07-24T23:59:59.000Z

60

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network [OSTI]

was approximately to heat- or load-follow. As in Baltimore,reviews of CHP cost and performance. no DG load-follow heat-follow optimal load-follow heat-follow optimal TOU CPP year

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Optimization Online - Group sparsity via linear-time projection  

E-Print Network [OSTI]

Jul 31, 2008 ... ... is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

Ewout van den Berg

2008-07-31T23:59:59.000Z

62

Engine valve actuation for combustion enhancement  

DOE Patents [OSTI]

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

2008-03-04T23:59:59.000Z

63

Engine Valve Actuation For Combustion Enhancement  

DOE Patents [OSTI]

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

2004-05-18T23:59:59.000Z

64

Dynamic Optimization in Continuous-Time Economic Models (A Guide for the Perplexed)  

E-Print Network [OSTI]

Dynamic Optimization in Continuous-Time Economic Models (A Guide for the Perplexed) Maurice, continuous-time modeling allows application of a powerful mathematical tool, the theory of optimal dynamic control. The basic idea of optimal control theory is easy to grasp-- indeed it follows from elementary

Sadoulet, Elisabeth

65

Optimal Real-Time Scheduling of Control Tasks with State Feedback Resource Allocation  

E-Print Network [OSTI]

1 Optimal Real-Time Scheduling of Control Tasks with State Feedback Resource Allocation Mohamed El for the optimal integrated control and real-time scheduling of control tasks. First, the problem of the optimal integrated control and non- preemptive off-line scheduling of control tasks in the sense of the H2

Paris-Sud XI, Université de

66

Compact, electro-hydraulic, variable valve actuation system providing...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Compact, electro-hydraulic, variable valve actuation system providing variable lift, timing and duration to enable high efficiency engine combustion control Compact,...

67

Real-time optimization boosts capacity of Korean olefins plant  

SciTech Connect (OSTI)

Real-time optimization (RTO) of Hyundai Petrochemical Co. Ltd.`s olefins complex at Daesan, South Korea, increased ethylene capacity 4% and revenues 12%, and decreased feedstock and energy usage 2.5%, with no changes in operating conditions. The project comprised RTO and advanced process control (APC) systems for the 350,000 metric ton/year (mty) ethylene plant. A similar system was implemented in the hydrotreating and benzene recovery sections of the plant`s pyrolysis-gasoline treating unit. Hyundai Petrochemical started up its olefins complex on Korea`s western seaboard in late 1991. The Daesan complex comprises 10 plants, including naphtha cracking, monomer, and polymer units. Additional support facilities include: industrial water treatment plants; electric generators; automatic storage systems; a jetty with capacity to berth 100,000 dwt and 10,000 dwt ships simultaneously; a research and development center. The plant`s capacity is 350,000 mty ethylene and 175,000 mty propylene, based on 7,200 operating hr/year. Since start-up, naphtha has been the primary feed, but the plant was designed with flexibility to process C{sub 3}/C{sub 4} (LPG) and gas oil feeds. This paper reviews the project management and decision making process along with the computerized control system design.

Yoon, S. [Hyundai Petrochemical Co. Ltd., Daesan (Korea, Republic of); Dasgupta, S.; Mijares, G. [M.W. Kellogg Co., Houston, TX (United States)

1996-06-17T23:59:59.000Z

68

Time-Optimal Control in Dc-Dc Converters: A Maximum Principle Perspective  

E-Print Network [OSTI]

the development of advanced nonlinear control methods [1], [2]. For instance, time-optimal and proximate time] establishes single-switch time-optimal control of buck converters and inverters; however, this has not been function to be minimized is of the form J(u) = tf t0 L(x(t), u(t))dt, (2) where tf denotes the terminal

Liberzon, Daniel

69

Optimal PID-Control for First Order Plus Time Delay Systems & Verification of the  

E-Print Network [OSTI]

Optimal PID-Control for First Order Plus Time Delay Systems & Verification of the SIMC Rules Chriss and Technology (NTNU), Trondheim, Norway e-mail: skoge@ntnu.no Abstract: Optimal cascade PID-settings are found with a modified SIMC-rule for PID- control (Figure 1). Optimality (performance) is defined in terms

Skogestad, Sigurd

70

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network [OSTI]

approximately to heat- or load-follow. Where there was awas approximately to heat- or load-follow. As in Baltimore,and performance. no DG load-follow heat-follow optimal load-

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

71

Optimal experiment design for time-lapse traveltime tomography  

SciTech Connect (OSTI)

Geophysical monitoring techniques offer the only noninvasive approach capable of assessing both the spatial and temporal dynamics of subsurface fluid processes. Increasingly, permanent sensor arrays in boreholes and on the ocean floor are being deployed to improve the repeatability and increase the temporal sampling of monitoring surveys. Because permanent arrays require a large up-front capital investment and are difficult (or impossible) to re-configure once installed, a premium is placed on selecting a geometry capable of imaging the desired target at minimum cost. We present a simple approach to optimizing downhole sensor configurations for monitoring experiments making use of differential seismic traveltimes. In our case, we use a design quality metric based on the accuracy of tomographic reconstructions for a suite of imaging targets. By not requiring an explicit singular value decomposition of the forward operator, evaluation of this objective function scales to problems with a large number of unknowns. We also restrict the design problem by recasting the array geometry into a low dimensional form more suitable for optimization at a reasonable computational cost. We test two search algorithms on the design problem: the Nelder-Mead downhill simplex method and the Multilevel Coordinate Search algorithm. The algorithm is tested for four crosswell acquisition scenarios relevant to continuous seismic monitoring, a two parameter array optimization, several scenarios involving four parameter length/offset optimizations, and a comparison of optimal multi-source designs. In the last case, we also examine trade-offs between source sparsity and the quality of tomographic reconstructions. One general observation is that asymmetric array lengths improve localized image quality in crosswell experiments with a small number of sources and a large number of receivers. Preliminary results also suggest that high-quality differential images can be generated using only a small number of optimally positioned sources.

Ajo-Franklin, J.B.

2009-10-01T23:59:59.000Z

72

Optimal PID-Control on First Order Plus Time Delay Systems & Verification of the  

E-Print Network [OSTI]

Optimal PID-Control on First Order Plus Time Delay Systems & Verification of the SIMC Rules Chriss and Technology (NTNU), Trondheim, Norway e-mail: skoge@ntnu.no Abstract: Optimal PID-settings are found, and is the time delay. We consider only the cascade form PID-controller K(s) = Kc Is + 1 Is (Ds + 1) (2) where Kc

Skogestad, Sigurd

73

Optimal Demand Bidding for Time-Shiftable Loads Hamed Mohsenian-Rad, Senior Member, IEEE  

E-Print Network [OSTI]

-ahead market, real-time market, demand side management, multi-stage stochastic optimization, closed1 Optimal Demand Bidding for Time-Shiftable Loads Hamed Mohsenian-Rad, Senior Member, IEEE Abstract and enhancing demand response and peak-load shaving programs. In this paper, we seek to answer the following

Mohsenian-Rad, Hamed

74

HYBRIDISATION OF NEURAL NETWORKS AND GENETIC ALGORITHMS FOR TIME-OPTIMAL CONTROL  

E-Print Network [OSTI]

into a time-energy optimal control problem which can be regarded as a Lagrangian constraint optimisation Chaiyaratana Department of Production Engineering King Mongkut's Institute of Technology North Bangkok 1518) are used to solve a multi-objective optimisation problem related to time-optimal control. The results

Coello, Carlos A. Coello

75

Optimal Real-time Dispatch for Integrated Energy Systems  

E-Print Network [OSTI]

electric utilities, distributed generation investmentDistributed Power Generation: Planning and Evaluation Marcel Dekker, New York. Appendix A. UTILITYDistributed Generation Investment Optimization With the recent advent of small (100s of kW to several MW) DG that is cost competitive with utility

Firestone, Ryan Michael

2007-01-01T23:59:59.000Z

76

A Comparison of Waterflood Management Using Arrival Time Optimization and NPV Optimization  

E-Print Network [OSTI]

permeability streaks could lead to an early water breakthrough at the producers and thus reduce the sweep efficiency in the field. One approach to counteract the impact of heterogeneity and to improve waterflood sweep efficiency is through optimal rate...

Tao, Qing

2011-02-22T23:59:59.000Z

77

Near Time-optimal Constrained Trajectory Planning on Outdoor Terrain  

E-Print Network [OSTI]

interactions are usually unaccounted for. Kinodynamic planning in real-time is also difficult and currently

Sukhatme, Gaurav S.

78

Multiscale simulations of the aortic heart valve : applications in disease and surgery  

E-Print Network [OSTI]

This thesis presents mathematical models describing the mechanical behavior of the human aortic heart valve over a range of length and time scales. In the human heart, the valves perform the vital function of controlling ...

Weinberg, Eli, 1979-

2008-01-01T23:59:59.000Z

79

Flow metering valve  

DOE Patents [OSTI]

An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

Blaedel, Kenneth L. (Dublin, CA)

1985-01-01T23:59:59.000Z

80

Flow metering valve  

DOE Patents [OSTI]

An apparatus for metering fluids at high pressures of about 20,000 to 60,000 psi is disclosed. The apparatus includes first and second plates which are positioned adjacent each other to form a valve chamber. The plates are made of materials which have substantially equal elastic properties. One plate has a planar surface area, and the other a recessed surface area defined by periphery and central lips. When the two plates are positioned in adjacent contacting relationship, a valve chamber is formed between the planar surface area and the recessed surface area. Fluid is introduced into the chamber and exits therefrom when a deformation occurs at positions where they no longer form a valve seat. This permits the metering of fluids at high pressures and at slow variable rates. Fluid then exits from the chamber until an applied external force becomes large enough to bring the valve seats back into contact.

Blaedel, K.L.

1983-11-03T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Valve for gas centrifuges  

DOE Patents [OSTI]

The invention is a pneumatically operated valve assembly for simultaneously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two of the lines so closed. The valve assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

Hahs, Charles A. (Oak Ridge, TN); Burbage, Charles H. (Oak Ridge, TN)

1984-01-01T23:59:59.000Z

82

Cost Optimal Operation of Thermal Energy Storage System with Real-Time Prices  

E-Print Network [OSTI]

Cost Optimal Operation of Thermal Energy Storage System with Real-Time Prices Toru Kashima, Member of the result [4]. The same can be said for time varying real-time prices. Real-time energy pricing is not yet such as chillers. Energy resources such as electricity or natural gas are bought from suppliers at certain prices

83

Optimal PID-Control on First Order Plus Time Delay Systems & Verification of the  

E-Print Network [OSTI]

Optimal PID-Control on First Order Plus Time Delay Systems & Verification of the SIMC Rules Chriss and Technology (NTNU), Trondheim, Norway e-mail: skoge@ntnu.no Abstract: Optimal PID-settings are found. We consider only the cascade form PID-controller K(s) = Kc Is + 1 Is (Ds + 1) (2) where Kc, I and D

Skogestad, Sigurd

84

Heterogeneous capital stocks and the optimal timing for CO2 abatement  

E-Print Network [OSTI]

Heterogeneous capital stocks and the optimal timing for CO2 abatement Mark Jaccard *, Nic Rivers a model and empirically estimated abatement costs. The results suggest that under many different assumptions, an early start at CO2 abatement for long-lived capital stocks would be economically optimal

85

Utility-Optimal Scheduling in Time-Varying Wireless Networks with Delay Constraints  

E-Print Network [OSTI]

propose an on-line scheduling policy and prove that it is utility- optimal. Surprisingly, this policy doesUtility-Optimal Scheduling in Time-Varying Wireless Networks with Delay Constraints I-Hong Hou CSL-varying environment, we consider the system problem of maximizing the total utility of clients, where the utilities

86

CONTROL OF A CLIMBING ROBOT USING REAL-TIME CONVEX OPTIMIZATION  

E-Print Network [OSTI]

is closed around desired robot chassis position to generate cartesian feedback forces. A convex optimization primarily on the planning problem. This paper focuses on the design of a control system. The target robotCONTROL OF A CLIMBING ROBOT USING REAL-TIME CONVEX OPTIMIZATION Teresa G. Miller Timothy W. Bretl

Ma, Yi

87

APPLICATION OF GENETIC ALGORITHMS TO THE MULTI-OBJECTIVE OPTIMIZATION OF THE INSPECTION TIMES OF A  

E-Print Network [OSTI]

APPLICATION OF GENETIC ALGORITHMS TO THE MULTI- OBJECTIVE OPTIMIZATION OF THE INSPECTION TIMES OF A SAFETY SYSTEM OF A PRESSURIZED WATER REACTOR Pietro Giuggioli Busacca, Marzio Marseguerra, Enrico Zio The purpose of this paper is to present an approach to optimization in which every target is considered

Coello, Carlos A. Coello

88

Optimization Online - Stochastic Real-Time Scheduling of Wind ...  

E-Print Network [OSTI]

Jan 3, 2015 ... Stochastic Real-Time Scheduling of Wind-thermal Generation Units in an Electric Utility. Alireza Soroudi (alireza.soroudi ***at*** ucd.ie)

Alireza Soroudi

2015-01-03T23:59:59.000Z

89

Optimization Online - Real-Time Dispatchability of Bulk Power ...  

E-Print Network [OSTI]

Mar 16, 2015 ... Real-Time Dispatchability of Bulk Power Systems with Volatile Renewable Generations. Wei Wei (wei-wei04 ***at*** mails.tsinghua.edu.cn)

Wei Wei

2015-03-16T23:59:59.000Z

90

Optimal Time-of-Use Pricing For Residential Load Control  

E-Print Network [OSTI]

a novel algorithm for finding an optimum time-of-use electricity pricing in monopoly utility markets implementing a demand response strategy. Finally, the effect of demand response in electricity prices to changes in the price of electricity over time via incentive payments designed to induce lower electricity

Kumar, Sunil

91

Optimal Stopping Rule for a Project with Uncertain Completion Time and Partial Salvageability  

E-Print Network [OSTI]

In this paper, we developed an optimal stopping model for the control of an investment project that takes an uncertain length of time to develop and can still provide a partial payoff even if it is terminated without ...

Chi, Tailan

1997-01-01T23:59:59.000Z

92

Energy-optimal schedules of real-time jobs with hard deadlines  

E-Print Network [OSTI]

In this thesis, we develop algorithms that make optimal use of frequency scaling to schedule jobs with real??time requirements. Dynamic voltage scaling is a technique used to reduce energy consumption in wide variety of systems. Reducing supply...

George, John Vijoe

2005-11-01T23:59:59.000Z

93

Fast closing valve  

DOE Patents [OSTI]

A valve is provided for protecting the high vacuum of a particle accelera in the event of air leakage, wherein the valve provides an axially symmetrical passage to avoid disturbance of the partical beam during normal operation, and yet enables very rapid and tight closure of the beam-carrying pipe in the event of air leakage. The valve includes a ball member (30) which can rotate between a first position wherein a bore (32) in the member is aligned with the beam pipe, and a second position out of line with the pipe. A seal member (38) is flexibly sealed to the pipe, and has a seal end which can move tightly against the ball member after the bore has rotated out of line with the pipe, to thereby assure that the seal member does not retard rapid rotation of the ball valve member. The ball valve member can be rapidly rotated by a conductive arm (40) fixed to it and which is rotated by the discharge of a capacitor bank through coils (44, 45) located adjacent to the arm.

Hanson, Clark L. (Livermore, CA)

1984-01-10T23:59:59.000Z

94

Locking apparatus for gate valves  

DOE Patents [OSTI]

A locking apparatus for fluid operated valves having a piston connected to the valve actuator which moves in response to applied pressure within a cylinder housing having a cylinder head, a catch block is secured to the piston, and the cylinder head incorporates a catch pin. Pressure applied to the cylinder to open the valve moves the piston adjacent to the cylinder head where the catch pin automatically engages the catch block preventing futher movement of the piston or premature closure of the valve. Application of pressure to the cylinder to close the valve, retracts the catch pin, allowing the valve to close. Included are one or more selector valves, for selecting pressure application to other apparatus depending on the gate valve position, open or closed, protecting such apparatus from damage due to premature closing caused by pressure loss or operational error.

Fabyan, Joseph (Livermore, CA); Williams, Carl W. (Manteca, CA)

1988-01-01T23:59:59.000Z

95

Self-regulating valve  

DOE Patents [OSTI]

A variable, self-regulating valve having a hydraulic loss coefficient proportional to a positive exponential power of the flow rate. The device includes two objects in a flow channel and structure which assures that the distance between the two objects is an increasing function of the flow rate. The range of spacing between the objects is such that the hydraulic resistance of the valve is an increasing function of the distance between the two objects so that the desired hydraulic loss coefficient as a function of flow rate is obtained without variation in the flow area.

Humphreys, D.A.

1982-07-20T23:59:59.000Z

96

Valve stem and packing assembly  

DOE Patents [OSTI]

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents over tightening of the retaining nut and the resulting excessive friction between stem and stem packing. 2 figures.

Wordin, J.J.

1991-09-03T23:59:59.000Z

97

Valve stem and packing assembly  

DOE Patents [OSTI]

A valve stem and packing assembly is provided in which a rotatable valve stem includes a first tractrix surface for sliding contact with a stem packing and also includes a second tractrix surface for sliding contact with a bonnet. Force is applied by means of a spring, gland flange, and gland on the stem packing so the stem packing seals to the valve stem and bonnet. This configuration serves to create and maintain a reliable seal between the stem packing and the valve stem. The bonnet includes a second complementary tractrix surface for contacting the second sliding tractrix surface, the combination serving as a journal bearing for the entire valve stem and packing assembly. The journal bearing so configured is known as a Schiele's pivot. The Schiele's pivot also serves to maintain proper alignment of the valve stem with respect to the bonnet. Vertical wear between the surfaces of the Schiele's pivot is uniform at all points of contact between the second sliding tractrix surface and the second complementary tractrix surface of a bonnet. The valve stem is connected to a valve plug by means of a slip joint. The valve is opened and closed by rotating the valve stem. The slip joint compensates for wear on the Schiele's pivot and on the valve plug. A ledge is provided on the valve bonnet for the retaining nut to bear against. The ledge prevents overtightening of the retaining nut and the resulting excessive friction between stem and stem packing.

Wordin, John J. (Bingham County, ID)

1991-01-01T23:59:59.000Z

98

Valve for gas centrifuges  

DOE Patents [OSTI]

The invention is pneumatically operated valve assembly for simulatenously (1) closing gas-transfer lines connected to a gas centrifuge or the like and (2) establishing a recycle path between two on the lines so closed. The value assembly is especially designed to be compact, fast-acting, reliable, and comparatively inexpensive. It provides large reductions in capital costs for gas-centrifuge cascades.

Hahs, C.A.; Rurbage, C.H.

1982-03-17T23:59:59.000Z

99

Time sub-optimal nonlinear PI and PID controllers applied to  

E-Print Network [OSTI]

1 Time sub-optimal nonlinear PI and PID controllers applied to longitudinal headway car control Minh-Duc Hua, Claude Samson Abstract Simple nonlinear PI and PID controllers combining time, the proposed PID solution is applied to the longitudinal headway control of a vehicle following another vehicle

Paris-Sud XI, Université de

100

Near Optimal Demand-Side Energy Management Under Real-time Demand-Response Pricing  

E-Print Network [OSTI]

Near Optimal Demand-Side Energy Management Under Real-time Demand-Response Pricing Jin Xiao, Jae--In this paper, we present demand-side energy manage- ment under real-time demand-response pricing as a task, demand-response, energy management I. INTRODUCTION The growing awareness of global climate change has

Boutaba, Raouf

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Multi-port valve assembly  

DOE Patents [OSTI]

A multi-port fluid valve apparatus is used to control the flow of fluids through a plurality of valves and includes a web, which preferably is a stainless steel endless belt. The belt has an aperture therethrough and is progressed, under motor drive and control, so that its aperture is moved from one valve mechanism to another. Each of the valve mechanisms comprises a pair of valve blocks which are held in fluid-tight relationship against the belt. Each valve block consists of a block having a bore through which the fluid flows, a first seal surrounding the bore and a second seal surrounding the first seal, with the distance between the first and second seals being greater than the size of the belt aperture. In order to open a valve, the motor progresses the belt aperture to where it is aligned with the two bores of a pair of valve blocks, such alignment permitting a flow of the fluid through the valve. The valve is closed by movement of the belt aperture and its replacement, within the pair of valve blocks, by a solid portion of the belt.

Guggenheim, S. Frederic (Teaneck, NJ)

1986-01-01T23:59:59.000Z

102

Micro-valve pump light valve display  

DOE Patents [OSTI]

A flat panel display incorporates a plurality of micro-pump light valves (MLV's) to form pixels for recreating an image. Each MLV consists of a dielectric drop sandwiched between substrates, at least one of which is transparent, a holding electrode for maintaining the drop outside a viewing area, and a switching electrode from accelerating the drop from a location within the holding electrode to a location within the viewing area. The sustrates may further define non-wetting surface areas to create potential energy barriers to assist in controlling movement of the drop. The forces acting on the drop are quadratic in nature to provide a nonlinear response for increased image contrast. A crossed electrode structure can be used to activate the pixels whereby a large flat panel display is formed without active driver components at each pixel.

Yeechun Lee.

1993-01-19T23:59:59.000Z

103

Classification of heart valve condition using acoustic measurements  

SciTech Connect (OSTI)

Prosthetic heart valves and the many great strides in valve design have been responsible for extending the life spans of many people with serious heart conditions. Even though the prosthetic valves are extremely reliable, they are eventually susceptible to long-term fatigue and structural failure effects expected from mechanical devices operating over long periods of time. The purpose of our work is to classify the condition of in vivo Bjork-Shiley Convexo-Concave (BSCC) heart valves by processing acoustic measurements of heart valve sounds. The structural failures of interest for Bscc valves is called single leg separation (SLS). SLS can occur if the outlet strut cracks and separates from the main structure of the valve. We measure acoustic opening and closing sounds (waveforms) using high sensitivity contact microphones on the patient`s thorax. For our analysis, we focus our processing and classification efforts on the opening sounds because they yield direct information about outlet strut condition with minimal distortion caused by energy radiated from the valve disc.

Clark, G. [Lawrence Livermore National Lab., CA (United States)

1994-11-15T23:59:59.000Z

104

Curved butterfly bileaflet prosthetic cardiac valve  

DOE Patents [OSTI]

An annular valve body having a central passageway for the flow of blood therethrough with two curved leaflets each of which is pivotally supported on an accentric positioned axis in the central passageway for moving between a closed position and an open position. The leaflets are curved in a plane normal to the eccentric axis and positioned with the convex side of the leaflets facing each other when the leaflets are in the open position. Various parameters such as the curvature of the leaflets, the location of the eccentric axis, and the maximum opening angle of the leaflets are optimized according to the following performance criteria: maximize the minimum peak velocity through the valve, maximize the net stroke volume, and minimize the mean forward pressure difference, thereby reducing thrombosis and improving the hemodynamic performance.

McQueen, David M. (185 Hillside Ave., Chatham, NJ 07928); Peskin, Charles S. (186 Harrard Dr., Hartsdale, NY 10530)

1991-06-25T23:59:59.000Z

105

Fast-acting valve and uses thereof  

DOE Patents [OSTI]

A very fast acting valve capable of producing a very well-defined plug of gas suitable for filling a theta pinch vacuum vessel is given. The valve requires no springs, instead being stopped mainly by a nonlinear force. Thus, the valve is not subject to bouncing; and the ratio of the size of the valve housing to the size of the valve stem is smaller than it would be if springs were needed to stop the valve stem. Furthermore, the valve can be used for thousands of valve firings with no apparent valve damage.

Meyer, James A. (Espanola, NM)

1982-01-01T23:59:59.000Z

106

Fast-acting valve and uses thereof  

DOE Patents [OSTI]

A very fast acting valve capable of producing a very well-defined plug of gas suitable for filling a theta pinch vacuum vessel is given. The valve requires no springs, instead being stopped mainly by a nonlinear force. Thus, the valve is not subject to bouncing; and the ratio of the size of the valve housing to the size of the valve stem is smaller than it would be if springs were needed to stop the valve stem. Furthermore, the valve can be used for thousands of valve firings with no apparent valve damage.

Meyer, J.A.

1980-05-16T23:59:59.000Z

107

EVALUATION OF SPRING OPERATED RELIEF VALVE MAINTENANCE INTERVALS AND EXTENSION OF MAINTENANCE TIMES USING A WEIBULL ANALYSIS WITH MODIFIED BAYESIAN UPDATING  

SciTech Connect (OSTI)

The Savannah River Site (SRS) spring operated pressure relief valve (SORV) maintenance intervals were evaluated using an approach provided by the American Petroleum Institute (API RP 581) for risk-based inspection technology (RBI). In addition, the impact of extending the inspection schedule was evaluated using Monte Carlo Simulation (MCS). The API RP 581 approach is characterized as a Weibull analysis with modified Bayesian updating provided by SRS SORV proof testing experience. Initial Weibull parameter estimates were updated as per SRS's historical proof test records contained in the Center for Chemical Process Safety (CCPS) Process Equipment Reliability Database (PERD). The API RP 581 methodology was used to estimate the SORV's probability of failing on demand (PFD), and the annual expected risk. The API RP 581 methodology indicates that the current SRS maintenance plan is conservative. Cost savings may be attained in certain mild service applications that present low PFD and overall risk. Current practices are reviewed and recommendations are made for extending inspection intervals. The paper gives an illustration of the inspection costs versus the associated risks by using API RP 581 Risk Based Inspection (RBI) Technology. A cost effective maintenance frequency balancing both financial risk and inspection cost is demonstrated.

Harris, S.; Gross, R.; Mitchell, E.

2011-01-18T23:59:59.000Z

108

Optimal Battery Configuration in a Residential Home with Time-of-Use Pricing  

E-Print Network [OSTI]

is higher. Energy arbitrage leverages these different energy prices by buying the extra energy when the prices are low, storing it in an energy storage device and then using the stored energy when the priceOptimal Battery Configuration in a Residential Home with Time-of-Use Pricing Baris Aksanli

Simunic, Tajana

109

Lagrangian Structures in Very High-Frequency Radar Data and Optimal Pollution Timing  

E-Print Network [OSTI]

Lagrangian Structures in Very High-Frequency Radar Data and Optimal Pollution Timing Francois radar-based pollution release scheme using the hidden flow structure reduces the effect of industrial pollution in the coastal environment. INTRODUCTION The release of pollution in coastal areas [1, 2, 3] can

Marsden, Jerrold

110

Complete Automation of Future Grid for Optimal Real-Time Distribution of Renewables  

E-Print Network [OSTI]

Complete Automation of Future Grid for Optimal Real-Time Distribution of Renewables Kiyoshi integrates tie-set graph theory with an intelligent agent system, is presented to distribute renewable energy and renewable generation is highly variable and unpredictable. Simulation results on a one hundred-node network

Loudon, Catherine

111

Marginal abatement cost curves and the optimal timing of mitigation measures  

E-Print Network [OSTI]

Marginal abatement cost curves and the optimal timing of mitigation measures Adrien Vogt-Schilb 1, Washington D.C., USA Abstract Decision makers facing abatement targets need to decide which abatement mea- sures to implement, and in which order. Measure-explicit marginal abatement cost curves depict the cost

Paris-Sud XI, Université de

112

Utility Driven Optimization of Real Time Data Broadcast Schedules Rinku Dewria,  

E-Print Network [OSTI]

Utility Driven Optimization of Real Time Data Broadcast Schedules Rinku Dewria, , Indrakshi Rayb of portable computing devices thoroughly embedded in our day-to-day work and personal life. The de- vices addresses: rdewri@cs.du.edu (Rinku Dewri), iray@cs.colostate.edu (Indrakshi Ray), indrajit

Ray, Indrakshi

113

Semi-active compressor valve  

DOE Patents [OSTI]

A method and system for fine-tuning the motion of suction or discharge valves associated with cylinders of a reciprocating gas compressor, such as the large compressors used for natural gas transmission. The valve's primary driving force is conventional, but the valve also uses an electromagnetic coil to sense position of the plate (or other plugging element) and to provide an opposing force prior to impact.

Brun, Klaus (Helotes, TX); Gernentz, Ryan S. (San Antonio, TX)

2010-07-27T23:59:59.000Z

114

Streamline coal slurry letdown valve  

DOE Patents [OSTI]

A streamlined coal slurry letdown valve is featured which has a two-piece throat comprised of a seat and seat retainer. The two-piece design allows for easy assembly and disassembly of the valve. A novel cage holds the two-piece throat together during the high pressure letdown. The coal slurry letdown valve has long operating life as a result of its streamlined and erosion-resistance surfaces. 5 figs.

Platt, R.J.; Shadbolt, E.A.

1983-11-08T23:59:59.000Z

115

Internal combustion engine intake valve  

SciTech Connect (OSTI)

In a inlet valve for use in an internal combustion engine in which the valve has a stem and a head, the head having, when seated, a first side positioned within a combustion chamber of an engine block and a second, opposite, side attached to the stem, the second side including that piston of the head forming the seat with the engine block when the valve is in a seated position, and first side including that portion of the head from the seat toward the chamber when the valve is in the seated position, and the engine including means for moving the valve from the closed position to an open position to allow a fuel mixture to enter the chamber, the improvement in the valve comprising: an extension ridge from the first side, positioned in alignment with the periphery of the valve head, the ridge forming with the seat a single, continuous, smooth outer surface along the periphery thereof for reducing the coefficient of drag of the fuel entering the chamber around the valve head when the valve is in the open position.

Mosler, W.B.

1988-10-25T23:59:59.000Z

116

All metal valve structure for gas systems  

DOE Patents [OSTI]

A valve assembly with a resilient metal seat member is disclosed for providing a gas-tight seal in a gas handling system. The valve assembly also includes a valve element for sealing against the valve seat member; and an actuating means for operating the valve element. The valve seat member is a one-piece stainless steel ring having a central valve port and peripheral mounting flange, and an annular corrugation in between. A groove between the first and second ridges serves as a flexure zone during operation of the valve member and thus provides the seating pressure between the inner ridge or valve seat and the valve element. The outer annular ridge has a diameter less than said valve element to limit the seating motion of the valve element, preventing non-elastic deformation of the seat member.

Baker, Ray W. (Hamilton, OH); Pawlak, Donald A. (Centerville, OH); Ramey, Alford J. (Miamisburg, OH)

1984-11-13T23:59:59.000Z

117

Optimal use of time dependent probability density data to extract potential energy surfaces  

E-Print Network [OSTI]

A novel algorithm was recently presented to utilize emerging time dependent probability density data to extract molecular potential energy surfaces. This paper builds on the previous work and seeks to enhance the capabilities of the extraction algorithm: An improved method of removing the generally ill-posed nature of the inverse problem is introduced via an extended Tikhonov regularization and methods for choosing the optimal regularization parameters are discussed. Several ways to incorporate multiple data sets are investigated, including the means to optimally combine data from many experiments exploring different portions of the potential. Results are presented on the stability of the inversion procedure, including the optimal combination scheme, under the influence of data noise. The method is applied to the simulated inversion of a double well system.

Lukas Kurtz; Herschel Rabitz; Regina de Vivie-Riedle

2001-11-09T23:59:59.000Z

118

Surge-damping vacuum valve  

DOE Patents [OSTI]

A valve having a mechanism for damping out flow surges in a vacuum system which utilizes a slotted spring-loaded disk positioned adjacent the valve's vacuum port. Under flow surge conditions, the differential pressure forces the disk into sealing engagement with the vacuum port, thereby restricting the flow path to the slots in the disk damping out the flow surge.

Bullock, Jack C. (Pleasanton, CA); Kelly, Benjamin E. (Tracy, CA)

1980-01-01T23:59:59.000Z

119

Annular flow control safety valve  

SciTech Connect (OSTI)

A tubular housing having an inner tubular member forms an inner passageway inside of the inner member and an outer passageway between the inner member and the housing. The housing has valve openings leading from the outer passageway to the exterior of the housing and a tubular valve closure member telescopically moves on the interior of the housing. First means move the valve closure member in an upper direction for closing the openings and at least one actuating piston is telescopically movable within and has its longitudinal axis in the wall of the housing and engages the valve closure member. The piston is in communication with a hydraulic passageway adapted to extend to the well surface for actuating the closure member in a direction to open the valve openings. The closure member is positioned whereby upward flow through the outer passageway acts on the closure member to close the valve opening. At least one lockout piston telescopically moves within the housing and is actuated from the surface and is engageable with holding means in the housing for providing a hydraulic lockout for the valve. Shear means may be provided between the lockout piston and the housing for controlling the hydraulic lockout. A single seal is provided between the closure member and the housing and is positioned below the opening and exposed to the pressure on both sides when the valve is opened. Preferably the actuating pistons are connected to the valve closure member but the hydraulic lockout pistons engage but are unconnected to the valve closure member.

Black, P.W.; Pringle, R.E.

1981-06-16T23:59:59.000Z

120

Commissioning, Operation, Real Time Monitoring and Evaluation of Pilot: Achieving Optimal Performance through Building Commissioning  

E-Print Network [OSTI]

BUILDINGS ENERGY EFFICIENCY CONSORTIUM U.S. - CHINA CLEAN ENERGY RESEARCH CENTER (CERC-BEE) E3: Commissioning, Operation, Real Time Monitoring and Evaluation of Pilot Achieving Optimal Performance through Building Commissioning Xiufeng Pang... for the Sustainable performance of Buildings Xiufeng Pang, Ph.D, P.E. 5 Cx Workshop Topic Covered Introduction of building Cx in the U.S., the standards and guidelines Building enclosure Cx New building Cx and LEED Cx requirements Existing building Cx...

Pang,X.; Piette, M.A.; Hao,B.

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Cavitation guide for control valves  

SciTech Connect (OSTI)

This guide teaches the basic fundamentals of cavitation to provide the reader with an understanding of what causes cavitation, when it occurs, and the potential problems cavitation can cause to a valve and piping system. The document provides guidelines for understanding how to reduce the cavitation and/or select control valves for a cavitating system. The guide provides a method for predicting the cavitation intensity of control valves, and how the effect of cavitation on a system will vary with valve type, valve function, valve size, operating pressure, duration of operation and details of the piping installation. The guide defines six cavitation limits identifying cavitation intensities ranging from inception to the maximum intensity possible. The intensity of the cavitation at each limit Is described, including a brief discussion of how each level of cavitation influences the valve and system. Examples are included to demonstrate how to apply the method, including making both size and pressure scale effects corrections. Methods of controlling cavitation are discussed providing information on various techniques which can be used to design a new system or modify an existing one so it can operate at a desired level of cavitation.

Tullis, J.P. [Tullis Engineering Consultants, Logan, UT (United States)

1993-04-01T23:59:59.000Z

122

Heart valve tissue engineering Frank Baaijens  

E-Print Network [OSTI]

Heart valve tissue engineering Frank Baaijens Department of Biomedical Engineering Eindhoven University of Technology Netherlands Tissue engineered heart valves appear promising as autologous valvular functionality and durability of the heart valve relies on the strength and anisotropic properties of the valve

Stavroulakis, Georgios E.

123

CONTROL VALVE TESTING PROCEDURES AND EQUATIONS  

E-Print Network [OSTI]

a coefficient that is independent of valve size and constant for geometrically similar valves. However in the publication "Control Valve Flow Coefficients" by Rahmeyer and Driskell and published in the Pipeline Journal of ASCE. Testing Procedures The flow coefficient is experimentally determined for different valve openings

Rahmeyer, William J.

124

Multi-port valve  

DOE Patents [OSTI]

A multi-port valve is described for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO{sub 2}) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets there through disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending there through disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind. 7 figs.

Lewin, K.F.

1997-04-15T23:59:59.000Z

125

Multi-port valve  

DOE Patents [OSTI]

A multi-port valve for regulating, as a function of ambient air having varying wind velocity and wind direction in an open-field control area, the distribution of a fluid, particularly carbon dioxide (CO.sub.2) gas, in a fluid distribution system so that the control area remains generally at an elevated fluid concentration or level of said fluid. The multi-port valve generally includes a multi-port housing having a plurality of outlets therethrough disposed in a first pattern of outlets and at least one second pattern of outlets, and a movable plate having a plurality of apertures extending therethrough disposed in a first pattern of apertures and at least one second pattern of apertures. The first pattern of apertures being alignable with the first pattern of outlets and the at least one second pattern of apertures being alignable with the second pattern of outlets. The first pattern of apertures has a predetermined orientation with the at least one second pattern of apertures. For an open-field control area subject to ambient wind having a low velocity from any direction, the movable plate is positioned to equally distribute the supply of fluid in a fluid distribution system to the open-field control area. For an open-field control area subject to ambient wind having a high velocity from a given direction, the movable plate is positioned to generally distribute a supply of fluid in a fluid distribution system to that portion of the open-field control area located upwind.

Lewin, Keith F. (Calverton, NY)

1997-04-15T23:59:59.000Z

126

Growth Optimal Portfolios in Discrete-time Markets Under Transaction Costs  

E-Print Network [OSTI]

We investigate portfolio selection problem from a signal processing perspective and study how an investor should distribute wealth over two assets in order to maximize the cumulative wealth. We construct portfolios that provide the optimal growth in i.i.d. discrete time two-asset markets under proportional transaction costs. As the market model, we consider arbitrary discrete distributions on the price relative vectors, which can also be used to approximate a wide class of continuous distributions. To achieve optimal growth, we use threshold portfolios, where we introduce a recursive update to calculate the expected wealth. We then demonstrate that under the threshold rebalancing framework, the achievable set of portfolios elegantly form an irreducible Markov chain under mild technical conditions. We evaluate the corresponding stationary distribution of this Markov chain, which provides a natural and efficient method to calculate the cumulative expected wealth. Subsequently, the corresponding parameters are o...

Tunc, Sait; Kozat, Suleyman S

2012-01-01T23:59:59.000Z

127

Light incoherence theory revisited by Heisenberg time-energy uncertainty challenges solar cell optimization  

E-Print Network [OSTI]

Optimization of the efficiency of solar cells is a major challenge for renewable energies. Using a rigorous theoretical approach, we show that the photocurrent generated in a solar cell depends strongly on the degree of coherence of the incident light. In accordance with Heisenberg uncertainty time-energy, incoherent light at photons of carrier energy lower than the active material bandgap can be absorbed whereas coherent light at the same carrier energy cannot. We identify cases where incoherence does enhance efficiency. This result has a dramatical impact on the way solar cells must be optimized regarding sunlight. As an illustration, surface-corrugated GaAs and c-Si thin-film solar cells are considered.

Herman, Aline; Deparis, Olivier

2014-01-01T23:59:59.000Z

128

Classification of prosthetic heart valve sounds. A parametric approach  

SciTech Connect (OSTI)

People with heart problems have had their lives extended considerably with the development of the prosthetic heart valve. Great strides have been made in the development of the valves through the use of improved materials as well as efficient mechanical designs. However, since the valves operate continuously over a long period, structural failures can occur-even though they are relatively uncommon. Here the development of techniques to classify the valve either as having intact struts or as having a separated strut, commonly called single leg separation, is discussed. In this paper the signal processing techniques employed to extract the required signals/parameters are briefly reviewed and then it is shown how they can be used to simulate a synthetic heart valve database for eventual Monte Carlo testing. Next, the optimal classifier is developed under assumed conditions and its performance is compared to that of an adpative-type classifier implemented with a probabilistic neural network. Finally, the adaptive classifier is applied to a data set and its performance is analyzed. Based on synthetic data it is shown that excellent performance of the classifiers can be achieved implying a potentially robust solution to this classification problem. 21 refs., 11 figs., 1 tab.

Candy, J.V.; Jones, H.E. [Univ. of California, Livermore, CA (United States)]|[Lawrence Livermore National Lab., CA (United States)

1995-06-01T23:59:59.000Z

129

Real-Time Combined Heat and Power Operational Strategy Using a Hierarchical Optimization Algorithm  

SciTech Connect (OSTI)

Existing attempts to optimize the operation of Combined Heat and Power (CHP) systems for building applications have two major limitations: the electrical and thermal loads are obtained from historical weather profiles; and the CHP system models ignore transient responses by using constant equipment efficiencies. This paper considers the transient response of a building combined with a hierarchical CHP optimal control algorithm to obtain a real-time integrated system that uses the most recent weather and electric load information. This is accomplished by running concurrent simulations of two transient building models. The first transient building model uses current as well as forecast input information to obtain short term predictions of the thermal and electric building loads. The predictions are then used by an optimization algorithm, i.e., a hierarchical controller, that decides the amount of fuel and of electrical energy to be allocated at the current time step. In a simulation, the actual physical building is not available and, hence, to simulate a real-time environment, a second, building model with similar but not identical input loads are used to represent the actual building. A state-variable feedback loop is completed at the beginning of each time step by copying, i.e., measuring, the state variable from the actual building and restarting the predictive model using these ?measured? values as initial conditions. The simulation environment presented in this paper features nonlinear effects such as the dependence of the heat exchanger effectiveness on their operating conditions. The results indicate that the CHP engine operation dictated by the proposed hierarchical controller with uncertain weather conditions have the potential to yield significant savings when compared to conventional systems using current values of electricity and fuel prices.

Yun, Kyung Tae; Cho, Heejin; Luck, Rogelio; Mago, Pedro J.

2011-06-01T23:59:59.000Z

130

MIDWEST ISO CO-OPTIMIZATION BASED REAL-TIME DISPATCH AND PRICING OF ENERGY AND ANCILLARY SERVICES  

E-Print Network [OSTI]

day-ahead counterpart, real-time locational marginal prices (LMP) are calculated every fiveMIDWEST ISO CO-OPTIMIZATION BASED REAL-TIME DISPATCH AND PRICING OF ENERGY AND ANCILLARY SERVICES-time dispatch and pricing. The RT SCED formulation at the core of the real-time dispatch and pricing market

Tesfatsion, Leigh

131

The NV center as a quantum actuator: time-optimal control of nuclear spins  

E-Print Network [OSTI]

Indirect control of qubits by a quantum actuator has been proposed as an appealing strategy to manipulate qubits that couple only weakly to external fields. While universal quantum control can be easily achieved when the actuator-qubit coupling is anisotropic, the efficiency of this approach is less clear. Here we analyze the time-efficiency of the quantum actuator control. We describe a strategy to find time-optimal control sequence by the quantum actuator and compare their gate times with direct driving, identifying regimes where the actuator control performs faster. As an example, we focus on a specific implementation based on the Nitrogen-Vacancy center electronic spin in diamond (the actuator) and nearby carbon-13 nuclear spins (the qubits).

Clarice D. Aiello; Paola Cappellaro

2014-10-21T23:59:59.000Z

132

Valves - current operating experience of slurry valves (block and letdown) in coal liquefaction processes. Third quarter report  

SciTech Connect (OSTI)

This paper summarizes the recent letdown and block valve experience in the liquefaction pilot plants. Also included is a brief description of the research and development activities on valves which are conducted in supporting laboratories. The purpose of the summary is to concentrate on critical component problems common to all liquefaction plants, to avoid duplication of efforts, and to help provide timely solutions to the valve problems. The main source of information used in this paper is the Minutes of the Critical Component and Materials Meeting which is sponsored by the Office of Coal Processing, Fossil Energy, Department of Energy. Other sources of information such as the technical progress reports are also included based on availability and relevance to topics covered in this paper. It is intended that this report will be followed by updates as pertinent information concerning valves becomes available. In the subsequent sections of this paper a brief outline of past valve studies is given as background material followed by a summary of the most recent valve operating experience at the liquefaction plants.

NONE

1996-07-01T23:59:59.000Z

133

Annular flow diverter valve  

DOE Patents [OSTI]

A valve for diverting flow from the center of two concentric tubes to the annulus between the tubes or, operating in the reverse direction, for mixing fluids from concentric tubes into a common tube and for controlling the volume ratio of said flow consists of a toroidal baffle disposed in sliding engagement with the interior of the inner tube downstream of a plurality of ports in the inner tube, a plurality of gates in sliding engagement with the interior of the inner tube attached to the baffle for movement therewith, a servomotor having a bullet-shaped plug on the downstream end thereof, and drive rods connecting the servomotor to the toroidal baffle, the servomotor thereby being adapted to move the baffle into mating engagement with the bullet-shaped plug and simultaneously move the gates away from the ports in the inner tube and to move the baffle away from the bullet-shaped plug and simultaneously move the gates to cover the ports in the inner tube.

Rider, Robert L. (Walkersville, MD)

1980-01-01T23:59:59.000Z

134

Noninvasive valve monitor using alternating electromagnetic field  

DOE Patents [OSTI]

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Eissenberg, David M. (Oak Ridge, TN); Haynes, Howard D. (Knoxville, TN); Casada, Donald A. (Knoxville, TN)

1993-01-01T23:59:59.000Z

135

Adaptive Robust Control of Programmable Valves with Manufacturer Supplied Flow Mapping Only  

E-Print Network [OSTI]

and final tracking accuracy. In addition, real-time adaptation is used to reduce the degree of modelling-in and meter-out orifices [2], [3], [4] through valves number 1,2 and 4,5; and ii) enabling the precise control is the significant modelling error. The cartridge valves are of fast response and low cost but low accuracy

Yao, Bin

136

Active combustion flow modulation valve  

DOE Patents [OSTI]

A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.

Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W

2013-09-24T23:59:59.000Z

137

American Valve: Order (2010-CW-1411)  

Broader source: Energy.gov [DOE]

DOE ordered American Valve, Inc. to pay a $5,000 civil penalty after finding American Valve had failed to certify that certain showerhead models comply with the applicable water conservation standards.

138

Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control  

SciTech Connect (OSTI)

The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)

Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y. [PHILOSOPHIA, Inc., Seoul National University, San 56-1 Sillim-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

2006-07-01T23:59:59.000Z

139

Fast-acting valve actuator  

DOE Patents [OSTI]

A fast-acting valve actuator utilizes a spring driven pneumatically loaded piston to drive a valve gate. Rapid exhaust of pressurized gas from the pneumatically loaded side of the piston facilitates an extremely rapid piston stroke. A flexible selector diaphragm opens and closes an exhaust port in response to pressure differentials created by energizing and de-energizing a solenoid which controls the pneumatic input to the actuator as well as selectively providing a venting action to one side of the selector diaphragm.

Cho, Nakwon (Knoxville, TN)

1980-01-01T23:59:59.000Z

140

Lockout housing and sleeve for safety valve  

SciTech Connect (OSTI)

This patent describes apparatus for use in a subsurface valve. It comprises a lockout housing; and a lockout sleeve.

Dickson, R.L.; Davis, G.R.

1992-07-07T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Pressure relief valve/safety relief valve testing  

SciTech Connect (OSTI)

Pressure vessels and piping systems are protected form overpressurization by pressure relief valves. These safety features are required to be tested-inspected on some periodic basis and, in most cases witnessed by a third party inspector. As a result nonconformances found by third parties Westinghouse Hanford Company initiated a task team to develop a pressure safety program. This paper reveals their findings.

Murray, W.A.; Hamm, E.R.; Barber, J.R.

1994-02-01T23:59:59.000Z

142

Valve for fuel pin loading system  

DOE Patents [OSTI]

A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

Christiansen, D.W.

1984-01-01T23:59:59.000Z

143

Valve for fuel pin loading system  

DOE Patents [OSTI]

A cyclone valve surrounds a wall opening through which cladding is projected. An axial valve inlet surrounds the cladding. Air is drawn through the inlet by a cyclone stream within the valve. An inflatable seal is included to physically engage a fuel pin subassembly during loading of fuel pellets.

Christiansen, David W. (Kennewick, WA)

1985-01-01T23:59:59.000Z

144

DEGREES OF FREEDOM IN THE MISO BC WITH DELAYED-CSIT AND FINITE COHERENCE TIME: A SIMPLE OPTIMAL SCHEME  

E-Print Network [OSTI]

DEGREES OF FREEDOM IN THE MISO BC WITH DELAYED-CSIT AND FINITE COHERENCE TIME: A SIMPLE OPTIMAL the multi-input single-output (MISO) Broadcast Channel (BC), the multi-user (MU) downlink in a cell scheme was proposed in [9] for the time cor- related MISO broadcast channel with 2 users. This scheme

Gesbert, David

145

ON CONDITION MONITORING OF EXHAUST VALVES IN MARINE DIESEL ENGINES  

E-Print Network [OSTI]

with artificially in­ duced valve burn­through situations. The primary potential mon­ itoring measurements were engine performance. Further, during the expansion stroke at engine­builder specific timing, to lift its seat and thereby provide scavenge (from scavenge air system) of the polluted air in the cylinder

Mosegaard, Klaus

146

Valve assembly having remotely replaceable bearings  

DOE Patents [OSTI]

A valve assembly having remotely replaceable bearings is disclosed wherein a valve disc is supported within a flow duct for rotation about a pair of axially aligned bearings, one of which is carried by a spindle received within a diametral bore in the valve disc, and the other of which is carried by a bearing support block releasably mounted on the duct circumferentially of an annular collar on the valve disc coaxial with its diametrical bore. The spindle and bearing support block are adapted for remote removal to facilitate servicing or replacement of the valve disc support bearings.

Johnson, Evan R. (San Diego, CA); Tanner, David E. (Poway, CA)

1980-01-01T23:59:59.000Z

147

Sizing sliding gate valves for steam service  

SciTech Connect (OSTI)

Sliding gate valves have been used in thousands of applications during the past 40 yr. While steam control is a common application for these valves, thy are also used to control other gases and liquids. The sliding gate design provides straight-through flow, which minimizes turbulence, vibration, and noise. Seats are self-cleaning and self-lapping to provide a tight, long-lasting shutoff. A correctly sized valve is essential for accurate control. Valve size should be determined by service and system requirements, not by the size of the existing pipeline. Sizing a valve on the basis of pipeline size usually results in an oversized valve and poor control. Generally, regulator size is smaller than pipe size. Whenever complete information is known (inlet pressure, outlet pressure, or pressure drop, and required flow), determine the valve flow coefficient (C{sub v}) using the equations in ANSI/ISA S75.01 or a flow sizing chart. Tables of values for various types of valves are available from manufacturers. However, when complete system requirements are not known, valve oversizing is prevented by determining the design capacity of piping downstream from the valve. The valve should not be sized to pass more flow than the maximum amount the pipe can handle at a reasonable velocity. An example calculation is given.

Bollinger, R. [Jordan Value, Cincinnati, OH (United States)

1995-11-06T23:59:59.000Z

148

Evaluation of silicon-nitride ceramic valves.  

SciTech Connect (OSTI)

Silicon-nitride ceramic valves can improve the performance of both light- and heavy-duty automotive engines because of the superior material properties of silicon nitrides over current metal alloys. However, ceramics are brittle materials that may introduce uncertainties in the reliability and durability of ceramic valves. As a result, the lifetime of ceramic valves are difficult to predict theoretically due to wide variations in the type and distribution of microstructural flaws in the material. Nondestructive evaluation (NDE) methods are therefore required to assess the quality and reliability of these valves. Because ceramic materials are optically translucent and the strength-limiting flaws are normally located near the valve surface, a laser-scatter method can be used for NDE evaluation of ceramic valves. This paper reviews the progress in the development of this NDE method and its application to inspect silicon-nitride ceramic valves at various stages of manufacturing and bench and engine tests.

Sun, J. G.; Zhang, J. M.; Andrews, M. J.; Tretheway, J. S.; Phillips, N. S .L.; Jensen, J. A.; Nuclear Engineering Division; Univ. of Texas; Caterpillar, Inc.

2008-01-01T23:59:59.000Z

149

Hydraulically actuated fuel injector including a pilot operated spool valve assembly and hydraulic system using same  

DOE Patents [OSTI]

The present invention relates to hydraulic systems including hydraulically actuated fuel injectors that have a pilot operated spool valve assembly. One class of hydraulically actuated fuel injectors includes a solenoid driven pilot valve that controls the initiation of the injection event. However, during cold start conditions, hydraulic fluid, typically engine lubricating oil, is particularly viscous and is often difficult to displace through the relatively small drain path that is defined past the pilot valve member. Because the spool valve typically responds slower than expected during cold start due to the difficulty in displacing the relatively viscous oil, accurate start of injection timing can be difficult to achieve. There also exists a greater difficulty in reaching the higher end of the cold operating speed range. Therefore, the present invention utilizes a fluid evacuation valve to aid in displacement of the relatively viscous oil during cold start conditions.

Shafer, Scott F. (Morton, IL)

2002-01-01T23:59:59.000Z

150

Asymptotic behavior of the finite-time expected time-integrated negative part of some risk processes and optimal reserve allocation  

E-Print Network [OSTI]

heavy-tailed and light-tailed claim amount distributions are investigated. The time horizon may theory, heavy-tailed and light-tailed claim size distribution, risk measure, optimal reserve allocation. 1. Introduction The current change of regulation leads the insurance industry to address new

Boyer, Edmond

151

E-Print Network 3.0 - absent pulmonary valve Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

assessment of leaflet deformation and mechanical properties Summary: has four heart valves; the aortic valve, the pulmonary valve, the mitral valve and the tricuspid...

152

Capacity analysis, cycle time optimization, and supply chain strategy in multi-product biopharmaceutical manufacturing operations  

E-Print Network [OSTI]

Application of system optimization theory, supply chain principles, and capacity modeling are increasingly valuable tools for use in pharmaceutical manufacturing facilities. The dynamics of the pharmaceutical industry - ...

Fetcho-Phillips, Kacey L. (Kacey Lynn)

2011-01-01T23:59:59.000Z

153

approximate time-optimal control: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to be avoided) and good trajectories. However, many applications require also the optimization of quantitative measures of the trajectories retained by the controller, as...

154

Optimizing artificial lift operations through the use of wireless conveyed real time bottom hole data  

SciTech Connect (OSTI)

The use of an innovative wireless bottom hole pressure/temperature telemetry acquisition system in artificial lift operations can dramatically improve efficiency and optimize fluid producing rates in those wells. The tool is installed into the producing well in the vicinity of the perforations, measuring and transmitting the producing bottom hole pressures and temperatures to the surface for instantaneous control of the surface pumping motor speed. This insures the lowest possible fluid level back pressures, thus allowing for the highest possible fluid entry into the wellbore from that reservoir`s capacity. Operating costs per barrel are lowered since the maximum oil production can now be realized from existing wells. The telemetry tool is deployed with standard slickline equipment and is installed inside a well in a manner similar to ordinary pressure recorder tools. Several unique advantages of the tool are: (1) no moving parts; (2) no wireline to the surface; (3) real time measurement of bottom hole data; and (4) slickline retrievable. Future versions of the acquisition system tool will improve operating efficiency in the following ways: (1) Temperature monitoring and control of perforation scaling, tubular waxing, and tubular hydrating plugs. (2) Provide data necessary to create diagnostically predictive IPR curves through monitoring of reservoir in-flow rates. (3) Enabling early warning of water encroachment or lensing through fluid resistivity monitoring.

Campbell, B.; MacKinnon, J.; Bandy, T.R.; Hampton, T.

1996-12-31T23:59:59.000Z

155

Model for inventory management in valve manufacturing cell at Waters Corporation  

E-Print Network [OSTI]

This thesis addresses the challenges of improving the on-time delivery performance of a high-volume critical part type in a high-product-mix manufacturing facility of valves. Preliminary analysis on the push-type production ...

Yao, Bingxin

2013-01-01T23:59:59.000Z

156

Optimal Reactive Power Dispatch in Real-Time S. Salamat Sharif1  

E-Print Network [OSTI]

) an improvement in the volt- age profile and voltage stability, and 2) a savings in ac- tive power loss of view. A reduction in active power loss gained from ORPD can save a significant amount of money reactive power dispatch, power loss minimization, optimization methods 1 Introduction Optimal power

Taylor, James H.

157

The optimization problem Genetic Algorithm  

E-Print Network [OSTI]

The optimization problem Genetic Algorithm Particle Swarm Optimization Experimental results for time-power optimization META, October 27-31, 2014 1 / 25 #12;The optimization problem Genetic Algorithm Particle Swarm Optimization Experimental results Conclusions Time and energy optimization Traditionally

Giménez, Domingo

158

Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized for in situ applications  

E-Print Network [OSTI]

Quick extended x-ray absorption fine structure instrument with millisecond time scale, optimized of quick extended x-ray absorption fine structure QEXAFS and quick x-ray absorption near edge structure- tion spectroscopy XAS was developed in energy dispersive and quick extended x-ray absorption fine

Sparks, Donald L.

159

Miniature electrically operated diaphragm valve  

DOE Patents [OSTI]

The present invention provides a miniature electrically operated valve that can stand off significant pressures, that can be inexpensively produced, and that can be made to operate without continuous electrical power. A valve according to the present invention comprises a housing and a beam mounted with the housing. A diaphragm mounted with the housing forms a sealed fluid volume. An electromagnetic energy source, such as an electromagnetic coil, mounts with the housing and when energized urges the beam in one direction. The beam can be urged in the opposing direction by passive means or by reversing the polarity of the electromagnetic energy source or by a second electromagnetic energy source. Two fluid ports mount with the housing. A first fluid port mounts so that, as the beam is urged in one direction or the opposite, the beam urges the diaphragm to move between engaging and substantially sealing the fluid port and disengaging and not substantially sealing the fluid port. A seat can be mounted with the diaphragm to aid in sealing the fluid port. Latching mechanisms such as permanent magnets can be mounted so that the valve remains in the open or closed positions without continuous electrical power input. Fluid can flow through the housing between the two fluid ports when the diaphragm does not seal the first fluid port, but can be prevented from flowing by urging the beam so that the diaphragm seals the first fluid port. Various embodiments accommodate various latching mechanisms, electromagnetic energy sources, number of fluid ports, and diaphragm design considerations.

Adkins, Douglas R. (Albuquerque, NM); Spletzer, Barry L. (Albuquerque, NM); Wong, Chungnin C. (Albuquerque, NM); Frye-Mason, Gregory C. (Cedar Crest, NM); Fischer, Gary J. (Albuquerque, NM); Hesketh, Peter J. (Atlanta, GA)

2001-01-01T23:59:59.000Z

160

Control Optimization for a Chilled Water Thermal Storage System Under a Complicated Time-of-Use Electricity Rate Schedule  

E-Print Network [OSTI]

processes. A chiller start-stop optimization program was developed and implemented into the Energy Management and Control System (EMCS) to determine the number of chillers that need to be brought on line and the start and stop times for each chiller... every day, based on the prediction of the campus cooling load within the next 24 hours. With timely and accurate weather forecasting, the actual tank charging and discharging process closely matches the simulated process. The chiller plant...

Zhou, J.; Wei, G.; Turner, W.D.; Deng, S.; Claridge, D.E.; Contreras, O.

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Valve assembly for use with high temperature and high pressure fluids  

DOE Patents [OSTI]

The valve assembly for use with high temperature and high pressure fluids has inner and outer spaced shells and a valve actuator support of inner and outer spaced members which are connected at their end portions to the inner and outer shells, respectively, to extend substantially normal to the longitudinal axis of the inner shell. A layer of resilient heat insulating material covers the outer surfaces of the inner shell and the inner actuator support member and is of a thickness to only occupy part of the spaces between the inner and outer shells and inner and outer actuator support members. The remaining portion of the space between the inner and outer shells and the space between the inner and outer members is substantially filled with a body of castable, rigid refractory material. A movable valve member is disposed in the inner shell. A valve actuator assembly is supported in the valve actuator support to extend into the inner shell for connection with the movable valve member for movement of the movable valve member to positions from a fully open to a fully closed position to control flow of fluid through the inner shell. An anchor mneans is disposed adjacent opposite sides of the axis of the valve actuator support and attached to the inner shell so that relative radial movement between the inner and outer shell is permitted by the layer of resilient heat insulating material and relative longitudinal movement of the inner shell to the outer shell is permitted in opposite directions from the anchor means to thereby maintain the functional integrity of the movable valve member by providing an area of the inner shell surrounding the movable valve member longitdinally stationary, but at the same time allowing radial movement.

De Feo, Angelo (Totowa, NY)

1982-01-01T23:59:59.000Z

162

Miniature piezo electric vacuum inlet valve  

DOE Patents [OSTI]

A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability is disclosed. The low power (<1.6 watts), high pulse rate (<2 milliseconds), variable flow inlet valve is utilized for mass spectroscopic applications or other applications where pulsed or continuous flow conditions are needed. The inlet valve also has a very minimal dead volume of less than 0.01 std/cc. The valve can utilize, for example, a 12 Vdc input/750 Vdc, 3 mA output power supply compared to conventional piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three. 6 figs.

Keville, R.F.; Dietrich, D.D.

1998-03-24T23:59:59.000Z

163

Miniature piezo electric vacuum inlet valve  

DOE Patents [OSTI]

A miniature piezo electric vacuum inlet valve having a fast pulse rate and is battery operated with variable flow capability. The low power (<1.6 watts), high pulse rate (<2 milliseconds), variable flow inlet valve is utilized for mass spectroscopic applications or other applications where pulsed or continuous flow conditions are needed. The inlet valve also has a very minimal dead volume of less than 0.01 std/cc. The valve can utilize, for example, a 12 Vdc input/750 Vdc, 3 mA output power supply compared to conventional piezo electric valves which require preloading of the crystal drive mechanism and 120 Vac, thus the valve of the present invention is smaller by a factor of three.

Keville, Robert F. (Valley Springs, CA); Dietrich, Daniel D. (Livermore, CA)

1998-03-24T23:59:59.000Z

164

Half-metallic magnetism and the search for better spin valves  

SciTech Connect (OSTI)

We use a previously proposed theory for the temperature dependence of tunneling magnetoresistance to shed light on ongoing efforts to optimize spin valves. First, we show that a mechanism in which spin valve performance at finite temperatures is limited by uncorrelated thermal fluctuations of magnetization orientations on opposite sides of a tunnel junction is in good agreement with recent studies of the temperature-dependent magnetoresistance of high quality tunnel junctions with MgO barriers. Using this insight, we propose a simple formula which captures the advantages for spin-valve optimization of using materials with a high spin polarization of Fermi-level tunneling electrons, and of using materials with high ferromagnetic transition temperatures. We conclude that half-metallic ferromagnets can yield better spin-value performance than current elemental transition metal ferromagnet/MgO systems only if their ferromagnetic transition temperatures exceed ?950?K.

Everschor-Sitte, Karin; Sitte, Matthias; MacDonald, Allan H. [Department of Physics, The University of Texas at Austin, 2515 Speedway, Austin, Texas 78712 (United States)

2014-08-28T23:59:59.000Z

165

Propellant actuated nuclear reactor steam depressurization valve  

DOE Patents [OSTI]

A nuclear fission reactor combined with a propellant actuated depressurization and/or water injection valve is disclosed. The depressurization valve releases pressure from a water cooled, steam producing nuclear reactor when required to insure the safety of the reactor. Depressurization of the reactor pressure vessel enables gravity feeding of supplementary coolant water through the water injection valve to the reactor pressure vessel to prevent damage to the fuel core.

Ehrke, Alan C. (San Jose, CA); Knepp, John B. (San Jose, CA); Skoda, George I. (Santa Clara, CA)

1992-01-01T23:59:59.000Z

166

Valve and dash-pot assembly  

DOE Patents [OSTI]

A dash-pot valve comprising a cylinder submerged in the fluid of a housing and having a piston attached to a plunger projecting into the path of closing movement of a pivotal valve member. A vortex chamber in said cylinder is provided with tangentially directed inlets to generate vortex flow upon retraction of said plunger and effect increasing resistance against said piston to progressively retard the closing rate of said valve member toward its seat.

Chang, Shih-Chih (Richland, WA)

1986-01-01T23:59:59.000Z

167

Improved valve and dash-pot assembly  

DOE Patents [OSTI]

A dash-pot valve comprises a cylinder submerged in the fluid of a housing and have a piston attached to a plunger projecting into the path of closing movement of a pivotal valve member. A vortex chamber in said cylinder is provided with targentially directed inlets to generate vortex flow upon retraction of said plunger and effect increasing resistance against said piston to progressively retard the closing rate of said valve member toward its seat.

Chang, S.C.

1985-04-23T23:59:59.000Z

168

Materials for Advanced Engine Valve Train  

Broader source: Energy.gov (indexed) [DOE]

275,000 * FY11 Funding - 225,000 Budget * Changes in internal combustion regimes * Materials properties of exhaust valves will need to change to accommodate higher temperatures...

169

American Valve: Proposed Penalty (2010-CW-1411)  

Broader source: Energy.gov [DOE]

DOE alleged in a Notice of Proposed Civil Penalty that American Valve, Inc. failed to certify a variety of showerheads as compliant with the applicable water conservation standards.

170

Hydraulic engine valve actuation system including independent feedback control  

DOE Patents [OSTI]

A hydraulic valve actuation assembly may include a housing, a piston, a supply control valve, a closing control valve, and an opening control valve. The housing may define a first fluid chamber, a second fluid chamber, and a third fluid chamber. The piston may be axially secured to an engine valve and located within the first, second and third fluid chambers. The supply control valve may control a hydraulic fluid supply to the piston. The closing control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the second fluid chamber to the supply control valve. The opening control valve may be located between the supply control valve and the second fluid chamber and may control fluid flow from the supply control valve to the second fluid chamber.

Marriott, Craig D

2013-06-04T23:59:59.000Z

171

D0 Silicon Upgrade: Control Dewar Valve Calculations  

SciTech Connect (OSTI)

This engineering note documents the calculations that were done to support the valve size selection for the magnet flow control valve, EVMF in the solenoid control dewar. The size selected was a control valve with a Cv = 0.32.

Rucinski, Russ; /Fermilab

1995-10-20T23:59:59.000Z

172

Optimal adaptive routing and traffic assignment in stochastic time-dependent networks  

E-Print Network [OSTI]

A stochastic time-dependent (STD) network is defined by treating all link travel times at all time periods as random variables, with possible time-wise and link-wise stochastic dependency. A routing policy is a decision ...

Gao, Song, 1976-

2005-01-01T23:59:59.000Z

173

Cylinder valve packing nut studies  

SciTech Connect (OSTI)

The design, manufacture, and use of cylinder valve packing nuts have been studied to improve their resistance to failure from stress corrosion cracking. Stress frozen photoelastic models have been analyzed to measure the stress concentrations at observed points of failure. The load effects induced by assembly torque and thermal expansion of stem packing were observed by strain gaging nuts. The effects of finishing operations and heat treatment were studied by the strain gage hole boring and X-ray methods. Modifications of manufacturing and operation practices are reducing the frequency of stress corrosion failures.

Blue, S.C. [Martin Marietta Energy Systems, Inc., Paducah, KY (United States)

1991-12-31T23:59:59.000Z

174

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS--II: EXPRESS BRIEFS, VOL. 51, NO. 3, MARCH 2004 105 Continuous-Time Filter Design Optimized for  

E-Print Network [OSTI]

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS--II: EXPRESS BRIEFS, VOL. 51, NO. 3, MARCH 2004 105 Continuous-Time Filter Design Optimized for Reduced Die Area Charles Myers, Student Member, IEEE, Brandon for distributing capacitor and resistor area to optimally reduce die area in a given continuous-time filter design

Moon, Un-Ku

175

Characterization of the mitral valve using accelerated wear testing.  

E-Print Network [OSTI]

??There is a fundamental need for a better kind of long-term testing for artificial heart valves along with a biologically equivalent artificial mitral valve. Accelerated (more)

Riggan, Courtney N.

2010-01-01T23:59:59.000Z

176

Requirements for the Valve Train and Technolgies for Enabling...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

for the Valve Train and Technolgies for Enabling HCCI over the Entire Operating Range Requirements for the Valve Train and Technolgies for Enabling HCCI over the Entire Operating...

177

ISOLOK VALVE ACCEPTANCE TESTING FOR DWPF SME SAMPLING PROCESS  

SciTech Connect (OSTI)

Evaluation of the Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. Of the opportunities, a focus area related to optimizing the equipment and efficiency of the sample turnaround time for DWPF Analytical Laboratory was identified. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) evaluated the possibility of using an Isolok{reg_sign} sampling valve as an alternative to the Hydragard{reg_sign} valve for taking process samples. Previous viability testing was conducted with favorable results using the Isolok sampler and reported in SRNL-STI-2010-00749 (1). This task has the potential to improve operability, reduce maintenance time and decrease CPC cycle time. This report summarizes the results from acceptance testing which was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 (2) and which was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNL-RP-2011-00145 (3). The Isolok to be tested is the same model which was tested, qualified, and installed in the Sludge Receipt Adjustment Tank (SRAT) sample system. RW-0333P QA requirements apply to this task. This task was to qualify the Isolok sampler for use in the DWPF Slurry Mix Evaporator (SME) sampling process. The Hydragard, which is the current baseline sampling method, was used for comparison to the Isolok sampling data. The Isolok sampler is an air powered grab sampler used to 'pull' a sample volume from a process line. The operation of the sampler is shown in Figure 1. The image on the left shows the Isolok's spool extended into the process line and the image on the right shows the sampler retracted and then dispensing the liquid into the sampling container. To determine tank homogeneity, a Coliwasa sampler was used to grab samples at a high and low location within the mixing tank. Data from the two locations were compared to determine if the contents of the tank were well mixed. The Coliwasa sampler is a tube with a stopper at the bottom and is designed to obtain grab samples from specific locations within the drum contents. A position paper (4) was issued to address the prototypic flow loop issues and simulant selections. A statistically designed plan (5) was issued to address the total number of samples each sampler needed to pull, to provide the random order in which samples were pulled and to group samples for elemental analysis. The TTR required that the Isolok sampler perform as well as the Hydragard sampler during these tests to ensure the acceptability of the Isolok sampler for use in the DWPF sampling cells. Procedure No.L9.4-5015 was used to document the sample parameters and process steps. Completed procedures are located in R&D Engineering job folder 23269.

Edwards, T.; Hera, K.; Coleman, C.; Jones, M.; Wiedenman, B.

2011-12-05T23:59:59.000Z

178

Flex Fuel Optimized SI and HCCI Engine  

SciTech Connect (OSTI)

The central objective of the proposed work is to demonstrate an HCCI (homogeneous charge compression ignition) capable SI (spark ignited) engine that is capable of fast and smooth mode transition between SI and HCCI combustion modes. The model-based control technique was used to develop and validate the proposed control strategy for the fast and smooth combustion mode transition based upon the developed control-oriented engine; and an HCCI capable SI engine was designed and constructed using production ready two-step valve-train with electrical variable valve timing actuating system. Finally, smooth combustion mode transition was demonstrated on a metal engine within eight engine cycles. The Chrysler turbocharged 2.0L I4 direct injection engine was selected as the base engine for the project and the engine was modified to fit the two-step valve with electrical variable valve timing actuating system. To develop the model-based control strategy for stable HCCI combustion and smooth combustion mode transition between SI and HCCI combustion, a control-oriented real-time engine model was developed and implemented into the MSU HIL (hardware-in-the-loop) simulation environment. The developed model was used to study the engine actuating system requirement for the smooth and fast combustion mode transition and to develop the proposed mode transition control strategy. Finally, a single cylinder optical engine was designed and fabricated for studying the HCCI combustion characteristics. Optical engine combustion tests were conducted in both SI and HCCI combustion modes and the test results were used to calibrate the developed control-oriented engine model. Intensive GT-Power simulations were conducted to determine the optimal valve lift (high and low) and the cam phasing range. Delphi was selected to be the supplier for the two-step valve-train and Denso to be the electrical variable valve timing system supplier. A test bench was constructed to develop control strategies for the electrical variable valve timing (VVT) actuating system and satisfactory electrical VVT responses were obtained. Target engine control system was designed and fabricated at MSU for both single-cylinder optical and multi-cylinder metal engines. Finally, the developed control-oriented engine model was successfully implemented into the HIL simulation environment. The Chrysler 2.0L I4 DI engine was modified to fit the two-step vale with electrical variable valve timing actuating system. A used prototype engine was used as the base engine and the cylinder head was modified for the two-step valve with electrical VVT actuating system. Engine validation tests indicated that cylinder #3 has very high blow-by and it cannot be reduced with new pistons and rings. Due to the time constraint, it was decided to convert the four-cylinder engine into a single cylinder engine by blocking both intake and exhaust ports of the unused cylinders. The model-based combustion mode transition control algorithm was developed in the MSU HIL simulation environment and the Simulink based control strategy was implemented into the target engine controller. With both single-cylinder metal engine and control strategy ready, stable HCCI combustion was achived with COV of 2.1% Motoring tests were conducted to validate the actuator transient operations including valve lift, electrical variable valve timing, electronic throttle, multiple spark and injection controls. After the actuator operations were confirmed, 15-cycle smooth combustion mode transition from SI to HCCI combustion was achieved; and fast 8-cycle smooth combustion mode transition followed. With a fast electrical variable valve timing actuator, the number of engine cycles required for mode transition can be reduced down to five. It was also found that the combustion mode transition is sensitive to the charge air and engine coolant temperatures and regulating the corresponding temperatures to the target levels during the combustion mode transition is the key for a smooth combustion mode transition. As a summary, the proposed combust

Zhu, Guoming; Schock, Harold; Yang, Xiaojian; Huisjen, Andrew; Stuecken, Tom; Moran, Kevin; Zhen, Ron; Zhang, Shupeng

2013-09-30T23:59:59.000Z

179

High precision high flow range control valve  

DOE Patents [OSTI]

A fluid control valve is described having a valve housing having first and second valve housing openings for the ingress and egress of fluid through the control valve. Disposed within a void formed by the control valve is a sleeve having at least one sleeve opening to permit the flow of fluid therethrough. A flow restricter travels within the sleeve to progressively block off the sleeve opening and thereby control flow. A fluid passageway is formed between the first valve housing opening and the outer surface of the sleeve. A second fluid passageway is formed between the inside of the sleeve and the second valve housing opening. Neither fluid passageway contains more than one 90 [degree] turn. In the preferred embodiment only one of the two fluid passageways contains a 90[degree] turn. In another embodiment, the control valve housing is bifurcated by a control surface having control surface opening disposed therethrough. A flow restricter is in slidable contact with the control surface to restrict flow of fluid through the control surface openings. 12 figs.

McCray, J.A.

1999-07-13T23:59:59.000Z

180

High speed exhaust gas recirculation valve  

DOE Patents [OSTI]

In order to minimize pollutants such as Nox, internal combustion engines typically include an exhaust gas recirculation (EGR) valve that can be used to redirect a portion of exhaust gases to an intake conduit, such as an intake manifold, so that the redirected exhaust gases will be recycled. It is desirable to have an EGR valve with fast-acting capabilities, and it is also desirable to have the EGR valve take up as little space as possible. An exhaust gas recirculation valve is provided that includes an exhaust passage tube, a valve element pivotally mounted within the exhaust passage tube, a linear actuator; and a gear train. The gear train includes a rack gear operatively connected to the linear actuator, and at least one rotatable gear meshing with the rack gear and operatively connected to the valve element to cause rotation of the valve element upon actuation of the linear actuator. The apparatus provides a highly compact package having a high-speed valve actuation capability.

Fensom, Rod (Peterborough, GB); Kidder, David J. (Peterborough, GB)

2005-01-18T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Utility-based Time and Power Allocation on an Energy Harvesting Downlink: The Optimal  

E-Print Network [OSTI]

problem where the transmitter is aware of the energy arrival statistics of a frame before the frame starts harvest energy through solar cells, vibration absorption devices, thermoelectric generators, wind power on optimizing data transmission with an energy harvesting transmitter. A single-user communication system op

Uysal-Biyikoglu, Elif

182

Compatibility Study of Compile-Time Optimizations for Power and Reliability  

E-Print Network [OSTI]

, Christos Strydis and Georgi Gaydadjiev Computer Engineering Laboratory, Electrical Engineering Dept. Delft.N.Gaydadjiev} @ tudelft.nl Abstract--Historically compiler optimizations have been used mainly for improving embedded devices, power consumption becomes a crucial problem that is addressed by modern compilers. Biomedical

Kuzmanov, Georgi

183

Generic Mechanism of Optimal Energy Transfer Efficiency: A Scaling Theory of the Mean First Passage Time in Exciton Systems  

E-Print Network [OSTI]

An asymptotic scaling theory is presented using the conceptual basis of trapping-free subspace (i.e., orthogonal subspace) to establish the generic mechanism of optimal efficiency of excitation energy transfer (EET) in light-harvesting systems. Analogous to Kramers' turnover in classical rate theory, the enhanced efficiency in the weak damping limit and the suppressed efficiency in the strong damping limit define two asymptotic scaling regimes, which are interpolated to predict the functional form of optimal efficiency of the trapping-free subspace. In the presence of static disorder, the scaling law of transfer time with respect to dephasing rate changes from linear to square root, suggesting a weaker dependence on the environment. Though formulated in the context of EET, the analysis and conclusions apply in general to open quantum processes, including electron transfer, fluorescence emission, and heat conduction.

Wu, Jianlan; Silbey, Robert J

2013-01-01T23:59:59.000Z

184

Generic Mechanism of Optimal Energy Transfer Efficiency: A Scaling Theory of the Mean First Passage Time in Exciton Systems  

E-Print Network [OSTI]

An asymptotic scaling theory is presented using the conceptual basis of trapping-free subspace (i.e., orthogonal subspace) to establish the generic mechanism of optimal efficiency of excitation energy transfer (EET) in light-harvesting systems. Analogous to Kramers' turnover in classical rate theory, the enhanced efficiency in the weak damping limit and the suppressed efficiency in the strong damping limit define two asymptotic scaling regimes, which are interpolated to predict the functional form of optimal efficiency of the trapping-free subspace. In the presence of static disorder, the scaling law of transfer time with respect to dephasing rate changes from linear to square root, suggesting a weaker dependence on the environment. Though formulated in the context of EET, the analysis and conclusions apply in general to open quantum processes, including electron transfer, fluorescence emission, and heat conduction.

Jianlan Wu; Jianshu Cao; Robert J. Silbey

2012-07-26T23:59:59.000Z

185

Optimal Vehicle Routing with Real-Time Traffic Information Seongmoon Kim1  

E-Print Network [OSTI]

to accidents, bad weather, traffic con- gestion, etc., trucks hauling time-sensitive freight build "buffer time cost. Indeed a truck parked at the origin is less expensive than one that is in use. Moreover

Lewis, Mark E.

186

Near minimum-time maneuvers of large space structures using parameter optimization and lyapunov feedback control  

E-Print Network [OSTI]

Parameterization for Minimum-Time Control . . . . 28 28 29 35 39 V CONTROL PARAMETER APPROXIMATIONS. . Control Parameter Approximations for Near-Minimum Time Rest-to- Rest Maneuvers . . Rules of Thumb for Minimum-Time Rest-to-Rest Maneuvers Using the Bang-Bang... ControL One-Switch Bang-Bang Control Approximation . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . . . , , . . . . , . . Switch Time Approximations Bang-Bang Controls with an Even Number of Control Switches...

Carter, Michael Timothy

1993-01-01T23:59:59.000Z

187

Pressure compensated flow control valve  

DOE Patents [OSTI]

The invention is an air flow control valve which is capable of maintaining a constant flow at the outlet despite changes in the inlet or outlet pressure. The device consists of a shell assembly with an inlet chamber and outlet chamber separated by a separation plate. The chambers are connected by an orifice. Also located within the inlet chamber is a port controller assembly. The port controller assembly consists of a differential pressure plate and port cap affixed thereon. The cap is able to slide in and out of the orifice separating the inlet and outlet chambers. When the pressure differential is sufficient, the differential pressure plate rises or falls to maintain a constant air flow. Movement of the port controller assembly does not require the use of seals, diaphragms, tight tolerances, bushings, bearings, hinges, guides, or lubricants.

Minteer, Daniel J. (West Richland, WA)

1999-01-01T23:59:59.000Z

188

Whitey SCHe Ball Valves Provide Test Port Isolation  

SciTech Connect (OSTI)

These valves are 1/4-inch ball valves fabricated of 316 stainless steel. Packing is TFE (standard). They are used as normally closed isolation valves for test ports in the SCHe System between the gage root valve and the pressure indicator.

MISKA, C.R.

2000-10-19T23:59:59.000Z

189

Valve Cap For An Electric Storage Cell  

DOE Patents [OSTI]

The valve cap for an electric storage cell includes a central annular valve seat (23) and a membrane (5) fixed by its peripheral edge and urged against the seat by a piston (10) bearing thereagainst by means of a spring (12), the rear end of said spring (12) bearing on the endwall (8) of a chamber (20) formed in the cap and containing the piston (10) and the spring. A vent (19) puts the chamber (20) into communication with the atmosphere. A central orifice (26, 28) through the piston (10) and the membrane (5), enables gas from within the cell to escape via the top vent (19) when the valve opens.

Verhoog, Roelof (Bordeaux, FR); Genton, Alain (Merignac, FR)

2000-04-18T23:59:59.000Z

190

Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating  

DOE Patents [OSTI]

A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization. 14 figs.

Casada, D.A.

1996-01-16T23:59:59.000Z

191

Method and apparatus for monitoring motor operated valve motor output torque and power at valve seating  

DOE Patents [OSTI]

A method and apparatus are provided for monitoring a motor operated valve during the brief period when the valve seats and the torque switch trips to deenergize the valve motor. The method uses voltage measurements on the load side of a deenergizing switch that opens to deenergize the motor to determine, among other things, final motor rotational speed and the decelerating torque at motor deenergization.

Casada, Donald A. (Oak Ridge, TN)

1996-01-01T23:59:59.000Z

192

Optimization Online - A Note on the Ichoua et al (2003) Travel Time ...  

E-Print Network [OSTI]

Feb 2, 2012 ... Abstract: In this paper we exploit some properties of the travel time model proposed by Ichoua et al (2003), on which most of the current...

Guerriero Emanuela

2012-02-02T23:59:59.000Z

193

Discrete-Time Pricing and Optimal Exercise of American Perpetual Warrants in the Geometric Random Walk Model  

SciTech Connect (OSTI)

An American option (or, warrant) is the right, but not the obligation, to purchase or sell an underlying equity at any time up to a predetermined expiration date for a predetermined amount. A perpetual American option differs from a plain American option in that it does not expire. In this study, we solve the optimal stopping problem of a perpetual American option (both call and put) in discrete time using linear programming duality. Under the assumption that the underlying stock price follows a discrete time and discrete state Markov process, namely a geometric random walk, we formulate the pricing problem as an infinite dimensional linear programming (LP) problem using the excessive-majorant property of the value function. This formulation allows us to solve complementary slackness conditions in closed-form, revealing an optimal stopping strategy which highlights the set of stock-prices where the option should be exercised. The analysis for the call option reveals that such a critical value exists only in some cases, depending on a combination of state-transition probabilities and the economic discount factor (i.e., the prevailing interest rate) whereas it ceases to be an issue for the put.

Vanderbei, Robert J., E-mail: rvdb@princeton.edu [Princeton University, Department of Operations Research and Financial Engineering (United States); P Latin-Small-Letter-Dotless-I nar, Mustafa C., E-mail: mustafap@bilkent.edu.tr [Bilkent University, Department of Industrial Engineering (Turkey); Bozkaya, Efe B. [Sabanc Latin-Small-Letter-Dotless-I University, Faculty of Administrative Sciences (Turkey)] [Sabanc Latin-Small-Letter-Dotless-I University, Faculty of Administrative Sciences (Turkey)

2013-02-15T23:59:59.000Z

194

Valve studies: Hydrogen fluoride monitoring of UF{sub 6} cylinder valves  

SciTech Connect (OSTI)

Uranium hexafluoride (UF{sub 6}) cylinder valves have, like the cylinders, been in use and/or storage for periods ranging from 15 to 44 years. Visual inspection of the cylinders has shown that the extent of corrosion and the overall cylinder condition varies widely throughout the storage yards. One area of concern is the integrity of the cylinder valves. Visual inspection has found deposits which have been identified as radioactive material on or near the valves. These deposits suggest leakage of UF{sub 6} and may indicate valve degradation; however, these deposits may simply be residual material from cylinder filling operations.

Leedy, R.R.; Ellis, A.R.; Hoffmann, D.P.; Marsh, G.C. [and others

1996-08-01T23:59:59.000Z

195

Method for valve seating control for an electro-hydraulic engine valve  

DOE Patents [OSTI]

Valve lift in an internal combustion engine is controlled by an electro-hydraulic actuation mechanism including a selectively actuable hydraulic feedback circuit.

Sun, Zongxuan (Plymouth, MN)

2011-01-11T23:59:59.000Z

196

The aligned nuclear targets for investigation of time reversal invariance violation: thermal heating and optimization of target dimension  

E-Print Network [OSTI]

The thermal heating of aligned nuclear targets of HIO_3, LiIO_3 ans Sb target materials under neutron irradiation at JSNS is considered. It is shown that presently the targets of large volumes (several tens of cm^3) can be used in experiment. The optimal target dimensions are recommended for investigation with resonance neutrons. The use of proposed aligned targets at the new neutron spallation source JSNS (Japan) will make p[ossible to discover TRIV or decrease the present limit on the intensity of parity conserving time violating interaction by two-three order of magnitude.

A. G. Beda; A. S. Gerasimov

2007-06-18T23:59:59.000Z

197

A custom-designed limited-angle actuator for an electromechanical engine valve drive Part I: Conceptual design  

E-Print Network [OSTI]

Research has shown that variable valve timing (VVT) can improve significantly the performance of internal combustion (IC) engines, including higher fuel efficiencies, lower emissions, and larger torque outputs at each point ...

Qiu, Yihui

198

A custom-designed limited-angle actuator for an electromechanical engine valve drive Part II: Fabrication and evaluation  

E-Print Network [OSTI]

Research has shown that variable valve timing (VVT) can improve significantly the performance of internal combustion (IC) engines, including higher fuel efficiencies, lower emissions, and larger torque outputs at each point ...

Kassakian, John G.

199

Optimal Waterflood Management under Geologic Uncertainty Using Rate Control: Theory and Field Applications  

E-Print Network [OSTI]

Waterflood optimization via rate control is receiving increased interest because of rapid developments in the smart well completions and I-field technology. The use of inflow control valves (ICV) allows us to optimize the production/injection rates...

Alhuthali, Ahmed Humaid H.

2010-01-16T23:59:59.000Z

200

Frostless heat pump having thermal expansion valves  

DOE Patents [OSTI]

A heat pump system having an operable relationship for transferring heat between an exterior atmosphere and an interior atmosphere via a fluid refrigerant and further having a compressor, an interior heat exchanger, an exterior heat exchanger, a heat pump reversing valve, an accumulator, a thermal expansion valve having a remote sensing bulb disposed in heat transferable contact with the refrigerant piping section between said accumulator and said reversing valve, an outdoor temperature sensor, and a first means for heating said remote sensing bulb in response to said outdoor temperature sensor thereby opening said thermal expansion valve to raise suction pressure in order to mitigate defrosting of said exterior heat exchanger wherein said heat pump continues to operate in a heating mode.

Chen, Fang C. (Knoxville, TN); Mei, Viung C. (Oak Ridge, TN)

2002-10-22T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Install Removable Insulation on Valves and Fittings  

SciTech Connect (OSTI)

This revised ITP tip sheet on installing removable insulation on valves and fittings provides how-to advice for improving the system using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

202

The safety valve and climate policy  

E-Print Network [OSTI]

In discussions of a cap-and-trade system for implementation of Kyoto Protocol-type quantity targets, a "safety valve" was proposed where, by government sales of emissions permits at a fixed price, the marginal cost of the ...

Jacoby, Henry D.; Ellerman, A. Denny.

203

Project Development Specification for Valve Pit Manifold  

SciTech Connect (OSTI)

Establishes the performance, design development, and test requirements for the valve pit manifolds. The system engineering approach was used to develop this document in accordance with the guidelines laid out in the Systems Engineering Management Plan for Project W-314.

MCGREW, D.L.

2000-09-28T23:59:59.000Z

204

Self Contained Temperature Actuated Control Valves  

E-Print Network [OSTI]

There is a virtually unlimited potential for energy conservation by utilizing self contained temperature actuated valves. As steam costs soar it becomes more and more important to conserve feed stock dollars as well as the energy these dollars...

Pirkle, F.

1979-01-01T23:59:59.000Z

205

Well injection valve with retractable choke  

SciTech Connect (OSTI)

An injection valve is described for use in a well conduit consisting of: a housing having a bore, a valve closure member in the bore moving between open and closed positions, a flow tube telescopically movable in the housing for controlling the movement of the valve closure member, means for biasing the flow tube in a direction for allowing the valve closure member to move to the closed position, an expandable and contractible fluid restriction connected to the flow tube and extending into the bore for moving the flow tube to the open position in response to injection fluid, but allowing the passage of well tools through the valve, the restriction contractible in response to fluid flow, the restriction includes, segments movable into and out of the bore, and biasing means yieldably urging the segments into the bore, a no-go shoulder on the flow tube, and releasable lockout means between the flow tube and the housing for locking the flow tube and valve in the open position.

Pringle, R.E.

1986-07-22T23:59:59.000Z

206

Split Venturi, Axially-Rotated Valve  

DOE Patents [OSTI]

The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane.

Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY)

2000-08-29T23:59:59.000Z

207

Flow Split Venturi, Axially-Rotated Valve  

SciTech Connect (OSTI)

The present invention provides an axially-rotated valve which permits increased flow rates and lower pressure drop (characterized by a lower loss coefficient) by using an axial eccentric split venturi with two portions where at least one portion is rotatable with respect to the other portion. The axially-rotated valve typically may be designed to avoid flow separation and/or cavitation at full flow under a variety of conditions. Similarly, the valve is designed, in some embodiments, to produce streamlined flow within the valve. An axially aligned outlet may also increase the flow efficiency. A typical cross section of the eccentric split venturi may be non-axisymmetric such as a semicircular cross section which may assist in both throttling capabilities and in maximum flow capacity using the design of the present invention. Such a design can include applications for freeze resistant axially-rotated valves and may be fully-opened and fully-closed in one-half of a complete rotation. An internal wide radius elbow typically connected to a rotatable portion of the eccentric venturi may assist in directing flow with lower friction losses. A valve actuator may actuate in an axial manner yet be uniquely located outside of the axial flow path to further reduce friction losses. A seal may be used between the two portions that may include a peripheral and diametrical seal in the same plane. A seal separator may increase the useful life of the seal between the fixed and rotatable portions.

Walrath, David E. (Laramie, WY); Lindberg, William R. (Laramie, WY); Burgess, Robert K. (Sheridan, WY); LaBelle, James (Murrieta, CA)

2000-02-22T23:59:59.000Z

208

Adaptive real-time methodology for optimizing energy-efficient computing  

DOE Patents [OSTI]

Dynamic voltage and frequency scaling (DVFS) is an effective way to reduce energy and power consumption in microprocessor units. Current implementations of DVFS suffer from inaccurate modeling of power requirements and usage, and from inaccurate characterization of the relationships between the applicable variables. A system and method is proposed that adjusts CPU frequency and voltage based on run-time calculations of the workload processing time, as well as a calculation of performance sensitivity with respect to CPU frequency. The system and method are processor independent, and can be applied to either an entire system as a unit, or individually to each process running on a system.

Hsu, Chung-Hsing (Los Alamos, NM); Feng, Wu-Chun (Blacksburg, VA)

2011-06-28T23:59:59.000Z

209

Adaptive real-time methodology for optimizing energy-efficient computing  

DOE Patents [OSTI]

Dynamic voltage and frequency scaling (DVFS) is an effective way to reduce energy and power consumption in microprocessor units. Current implementations of DVFS suffer from inaccurate modeling of power requirements and usage, and from inaccurate characterization of the relationships between the applicable variables. A system and method is proposed that adjusts CPU frequency and voltage based on run-time calculations of the workload processing time, as well as a calculation of performance sensitivity with respect to CPU frequency. The system and method are processor independent, and can be applied to either an entire system as a unit, or individually to each process running on a system.

Hsu, Chung-Hsing; Feng, Wu-Chun

2013-01-29T23:59:59.000Z

210

Resource Optimization Subject to a Percentile Response Time SLA for Enterprise Computing  

E-Print Network [OSTI]

S metric is more realistic than the mean response time typically used in the literature. Numerical results negotiated QoS requirements for a given price. Figure 1 depicts a scenario for such an environment + · · · + nm cm) (1) subject to SLA constraints. Performance and price are the two most important components

Perros, Harry

211

Sub-Optimal Allocation of Time in Sequential Shih-Wei Wu1,2  

E-Print Network [OSTI]

, Laurence T. Maloney1,4 1 Department of Psychology, New York University, New York, New York, United States, 4 Center for Neural Science, New York University, New York, New York, United States of America Abstract The allocation of limited resources such as time or energy is a core problem that organisms face

Maloney, Laurence T.

212

"Optimal Market Grain Over Space and Time"* Nodir Adilov and Richard E. Schuler  

E-Print Network [OSTI]

is in the emerging markets for electricity where the spatial grain, locational marginal pricing (LMP) based of precise quantities of goods and services at particular locations and times; yet for convenience and to reduce transactions costs, these markets customarily specify the terms (e.g. the price) uniformly over

213

Self-Timed Resynchronization: A Post-Optimization for Static Multiprocessor Schedules  

E-Print Network [OSTI]

in the context of self-timed execution of iterative synchronous dataflow (SDF) [12] programs does not generally occur [13]. SDF has proven to be a useful model for representing a significant class of block diagrams. Examples of commercial tools based on SDF are the Signal Processing Worksystem (SPW) [17

214

Optimal Residential Load Control with Price Prediction in Real-Time  

E-Print Network [OSTI]

for both end users and utility companies. Keywords: Wholesale electricity market, real-time pricing, inclin and automatic residential energy con- sumption scheduling framework which attempts to achieve a desired trade to be used by the price predictor filter. Simulation results show that the combination of the proposed energy

Mohsenian-Rad, Hamed

215

Optimal Real-time Pricing Algorithm Based on Utility Maximization for Smart Grid  

E-Print Network [OSTI]

tool to develop efficient demand side management strategies, we propose a novel real-time pricing the need to develop new methods for demand side management (DSM). There is a wide range of DSM techniques consumption occurs in buildings [2]. In addition, the arising of new types of demand such as plug-in hybrid

Mohsenian-Rad, Hamed

216

A WEAR MODEL FOR DIESEL ENGINE EXHAUST VALVES  

SciTech Connect (OSTI)

The work summarized here comprises the concluding effort of a multi-year project, funded by the U.S. Department of Energy, Office of Vehicle Technologies. It supports the development of a better understanding of advanced diesel engine designs in which enhanced power density, energy efficiency, and emissions control place increasing demands upon the durability of engine materials. Many kinds of metallic alloys are used in engines depending on the operating stresses, temperatures, and chemical environments. Exhaust valves, for example, are subjected to high temperatures and repetitive surface contacts that place demands on durability and frictional characteristics of the materials. Valves must continue to seal the combustion chamber properly for thousands of hours of cyclic engine operation and under varying operating conditions. It was the focus of this effort to understand the wear processes in the valve-seat area and to develop a model for the surface deformation and wear of that important interface. An annotated bibliography is provided to illustrate efforts to understand valve wear and to investigate the factors of engine operation that affect its severity and physical manifestation. The project for which this modeling effort was the final task, involved construction of a high-temperature repetitive impact test system as well as basic tribology studies of the combined processes of mechanical wear plus oxidation at elevated temperatures. Several publications resulted from this work, and are cited in this report. The materials selected for the experimental work were high-performance alloys based on nickel and cobalt. In some cases, engine-tested exhaust valves were made available for wear analysis and to ensure that the modes of surface damage produced in experiments were simulative of service. New, production-grade exhaust valves were also used to prepare test specimens for experimental work along with the other alloy samples. Wear analysis of valves and seats run for hundreds of hours in heavy-duty diesels provided insights into the kinds of complexity that the contact conditions in engines can produce, and suggested the physical basis for the current approach to modeling. The model presented here involves four terms, two representing the valve response and two for its mating seat material. The model's structure assumes that wear that takes place under a complex combination of plastic deformation, tangential shear, and oxidation. Tribolayers form, are removed, and may reform. Layer formation affects the friction forces in the interface, and in turn, the energy available to do work on the materials to cause wear. To provide friction data for the model at various temperatures, sliding contact experiments were conducted from 22 to 850 C in a pin-on-disk apparatus at ORNL. In order to account for the behavior of different materials and engine designs, parameters in all four terms of the model can be adjusted to account for wear-in and incubation periods before the dominant wear processes evolve to their steady-state rates. For example, the deformation rate is assumed to be maximum during the early stages of operation, and then, due to material work-hardening and the increase in nominal contact area (which reduces the load per unit area), decreases to a lower rate at long times. Conversely, the rate of abrasion increases with time or number of cycles due to the build-up of oxides and tribo-layers between contact surfaces. The competition between deformation and abrasion results in complex, non-linear behavior of material loss per cycle of operation. Furthermore, these factors are affected by valve design features, such as the angle of incline of the valve seat. Several modeling scenarios are presented to demonstrate how the wear profile versus number of cycles changes in response to: (a) different relative abrasion rates of the seat and valve materials, (b) the friction coefficient as a function of temperature, (c) the relative deformation contribution of valve and seat materials, and (d) an interruption in the dominant we

Blau, Peter Julian [ORNL

2009-11-01T23:59:59.000Z

217

Simulant Development for Hanford Tank Farms Double Valve Isolation (DVI) Valves Testing  

SciTech Connect (OSTI)

Leakage testing of a representative sample of the safety-significant isolation valves for Double Valve Isolation (DVI) in an environment that simulates the abrasive characteristics of the Hanford Tank Farms Waste Transfer System during waste feed delivery to the Waste Treatment and Immobilization Plant (WTP) is to be conducted. The testing will consist of periodic leak performed on the DVI valves after prescribed numbers of valve cycles (open and close) in a simulated environment representative of the abrasive properties of the waste and the Waste Transfer System. The valve operations include exposure to cycling conditions that include gravity drain and flush operation following slurry transfer. The simulant test will establish the performance characteristics and verify compliance with the Documented Safety Analysis. Proper simulant development is essential to ensure that the critical process streams characteristics are represented, National Research Council report Advice on the Department of Energy's Cleanup Technology Roadmap: Gaps and Bridges

Wells, Beric E.

2012-12-21T23:59:59.000Z

218

Effects of aging and service wear on main steam isolation valves and valve operators  

SciTech Connect (OSTI)

In recent years main steam isolation valve (MSIV operating problems have resulted in significant operational transients (e.g., spurious reactor trips, steam generator dry out, excessive valve seat leakage), increased cost, and decreased plant availability. A key ingredient to an engineering-oriented reliability improvement effort is a thorough understanding of relevant historical experience. A detailed review of historical failure data available through the Institute of Nuclear Power Operation`s Nuclear Plant Reliability Data System has been conducted for several types of MSIVs and valve operators for both boiling-water reactors and pressurized-water reactors. The focus of this review is on MSIV failures modes, actuator failure modes, consequences of failure on plant operations, method of failure detection, and major stressors affecting both valves and valve operators.

Clark, R.L. [Oak Ridge National Lab., TN (United States)

1996-03-01T23:59:59.000Z

219

Unit commitment with valve-point loading effect  

E-Print Network [OSTI]

Apr 18, 2014 ... applied to a related problem: that of optimizing short-term hydro scheduling. ..... bounds is small enough (or the allowed CPU time is exceeded).

2014-04-18T23:59:59.000Z

220

Variance Optimal Hedging for discrete time processes with independent increments. Application to Electricity Markets  

E-Print Network [OSTI]

We consider the discretized version of a (continuous-time) two-factor model introduced by Benth and coauthors for the electricity markets. For this model, the underlying is the exponent of a sum of independent random variables. We provide and test an algorithm, which is based on the celebrated Foellmer-Schweizer decomposition for solving the mean-variance hedging problem. In particular, we establish that decomposition explicitely, for a large class of vanilla contingent claims. Interest is devoted in the choice of rebalancing dates and its impact on the hedging error, regarding the payoff regularity and the non stationarity of the log-price process.

Goutte, Stphane; Russo, Francesco

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Steam distribution and energy delivery optimization using wireless sensors  

SciTech Connect (OSTI)

The Extreme Measurement Communications Center at Oak Ridge National Laboratory (ORNL) explores the deployment of a wireless sensor system with a real-time measurement-based energy efficiency optimization framework in the ORNL campus. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize the energy delivery within the steam distribution system. We address the goal of achieving significant energy-saving in steam lines by monitoring and acting on leaking steam valves/traps. Our approach leverages an integrated wireless sensor and real-time monitoring capabilities. We make assessments on the real-time status of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observe the state measurements of these sensors. Our assessments are based on analysis of the wireless sensor measurements. We describe Fourier-spectrum based algorithms that interpret acoustic vibration sensor data to characterize flows and classify the steam system status. We are able to present the sensor readings, steam flow, steam trap status and the assessed alerts as an interactive overlay within a web-based Google Earth geographic platform that enables decision makers to take remedial action. We believe our demonstration serves as an instantiation of a platform that extends implementation to include newer modalities to manage water flow, sewage and energy consumption.

Olama, Mohammed M [ORNL; Allgood, Glenn O [ORNL; Kuruganti, Phani Teja [ORNL; Sukumar, Sreenivas R [ORNL; Djouadi, Seddik M [ORNL; Lake, Joe E [ORNL

2011-01-01T23:59:59.000Z

222

A Novel Fractional Order Fuzzy PID Controller and Its Optimal Time Domain Tuning Based on Integral Performance Indices  

E-Print Network [OSTI]

A novel fractional order (FO) fuzzy Proportional-Integral-Derivative (PID) controller has been proposed in this paper which works on the closed loop error and its fractional derivative as the input and has a fractional integrator in its output. The fractional order differ-integrations in the proposed fuzzy logic controller (FLC) are kept as design variables along with the input-output scaling factors (SF) and are optimized with Genetic Algorithm (GA) while minimizing several integral error indices along with the control signal as the objective function. Simulations studies are carried out to control a delayed nonlinear process and an open loop unstable process with time delay. The closed loop performances and controller efforts in each case are compared with conventional PID, fuzzy PID and PI{\\lambda}D{\\mu} controller subjected to different integral performance indices. Simulation results show that the proposed fractional order fuzzy PID controller outperforms the others in most cases.

Das, Saptarshi; Das, Shantanu; Gupta, Amitava; 10.1016/j.engappai.2011.10.004

2012-01-01T23:59:59.000Z

223

Optimal beam pattern to maximize inclusion residence time in an electron beam melting hearth  

SciTech Connect (OSTI)

Approximate probabilities of inclusion survival through an electron beam melting hearth are computed from nitride dissolution rates, flotation velocities, and residence times. Dissolution rates were determined by measuring shrinkage rates of pure TiN and nitrided sponge in small pools of molten titanium in an electron beam melting hearth. Flotation velocities were calculated using correlations for fluid flow around spheres, and show that particles sink or float unless their densities are extremely close to that of molten titanium. Flow field characteristics which lead to effective inclusion removal are discussed in terms of heat flux pattern required to produce them, based on the electron beam`s unique ability to impart a nearly arbitrary heat flux pattern to the melt surface.

Powell, A.; Pal, U. [Massachusetts Inst. of Tech., Cambridge, MA (United States); Avyle, J. van den [Sandia National Labs., Albuquerque, NM (United States)

1997-02-01T23:59:59.000Z

224

Measure Guideline: Condensing Boilers - Optimizing Efficiency and Response Time During Setback Operation  

SciTech Connect (OSTI)

Conventional wisdom surrounding space heating has told us a couple of things consistently for several years now: size the mechanical systems to the heating loads and setting the thermostat back at night will result in energy savings. The problem is these two recommendations oppose each other. A system that is properly sized to the heating load will not have the extra capacity necessary to recover from a thermostat setback, especially at design conditions. The implication of this is that, for setback to be successfully implemented, the heating system must be oversized. This issue is exacerbated further when an outdoor reset control is used with a condensing boiler, because not only is the system matched to the load at design, the outdoor reset control matches the output to the load under varying outdoor temperatures. Under these circumstances, the home may never recover from setback. Special controls to bypass the outdoor reset sensor are then needed. Properly designing a hydronic system for setback operation can be accomplished but depends on several factors. Determining the appropriateness of setback for a particular project is the first step. This is followed by proper sizing of the boiler and baseboard to ensure the needed capacity can be met. Finally, control settings must be chosen that result in the most efficient and responsive performance. This guide provides step by step instructions for heating contractors and hydronic designers for selecting the proper control settings to maximize system performance and improve response time when using a thermostat setback.

Arena, L.

2014-02-01T23:59:59.000Z

225

Integrated Energy System Dispatch Optimization  

E-Print Network [OSTI]

Energy System Dispatch Optimization Ryan Firestone, MichaelEnergy System Dispatch Optimization Ryan Firestone - Studentthe real-time dispatch optimization problem for a generic

Firestone, Ryan; Stadler, Michael; Marnay, Chris

2006-01-01T23:59:59.000Z

226

Novel design of a rotary valve using axiomatic design  

E-Print Network [OSTI]

Rotary valves have existed for millennia; and while they have developed tremendously since the first Roman valves, many of the same problems have persisted. The basic problems are caused by the coupling of functional ...

Peliks, Robert Bilgor

2005-01-01T23:59:59.000Z

227

A Data-Centric Approach to Optimize Time in Workflow-Based Business Process Yuqun Zhang, Dewayne E. Perry  

E-Print Network [OSTI]

on scheduling, that mathematically models the optimal resource allocation of business processes in terms to optimize it in workflow- based business processes. By applying our data-centric business process modeling the execution order of business activities. Accordingly, we develop efficient algorithms to approach optimal

Perry, Dewayne E.

228

Optimization Online - Unit commitment with valve-point loading effect  

E-Print Network [OSTI]

Apr 18, 2014 ... Citation: Technical Report: DCC-2014-05 Departamento de Cincia de Computadores Faculdade de Cincias da Universidade do Porto Porto,...

Joo Pedro Pedroso

2014-04-18T23:59:59.000Z

229

Michigan: General Motors Optimizes Engine Valve Technology | Department of  

Broader source: Energy.gov (indexed) [DOE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergyENERGYWomen OwnedofDepartment ofJared Temanson -ofMarc MorialMegan SlackDr. MichaelEnergy

230

Design and Implementation of Silicon Nitride Valves for Heavy...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

More Documents & Publications Durability of ACERT Engine Components Durability of ACERT Engine Components Advanced Materials for Lightweight Valve Train Components...

231

Analysis of Flow in Pilot Operated Safety and Relief Valve of Nuclear Reactor Coolant System  

SciTech Connect (OSTI)

When the POSRV equipped in a nuclear power plant opens in instant by a failure in coolant system of PWR, a moving shock wave generates, and propagates downstream of the valve, inducing a complicated unsteadiness. The moving shock wave may exert severe load to the structure. In this connection, a method of gradual opening of the valve is used to reduce the load acting on the wall at the downstream of the POSRV. In the present study, experiments and calculations are performed to investigate the detail unsteady flow at the various pipe units and the effect of valve opening time on the flow downstream of the valve. In calculation by using of air as working fluid, 2-dimensional, unsteady compressible Navier-Stokes equations are solved by finite volume method. It was found that when the incident shock wave passes through the pipe unit, it may experience diffraction, reflection and interaction with a vortex. Furthermore, the geometry of the pipe unit affects the reflection type of shock wave and changes the load acting on the wall of pipe unit. It was also turned out that the maximum force acting on the wall of the pipe unit becomes in order of T-junction, 108 deg. elbow and branch in magnitude, respectively. And, the results obtained that show that the rapid pressure rise due to the moving shock wave by instant POSRV valve opening is attenuated by employing the gradual opening. (authors)

Kwon, Soon-Bum; Lee, Dong-Won [Department of Mechanical Engineering, Kyungpook National University, 1370, Sankyuk-dong, Daegu 702-701 (Korea, Republic of); Kim, In-Goo; Ahn, Hyung-Joon; Kim, Hho-Jung [Korea Institute of Nuclear Safety, 19, Kusungdong, Yousungku, Daejon 305-338 (Korea, Republic of)

2004-07-01T23:59:59.000Z

232

"Non-Reflective" Boundary Design via Remote Sensing and PID Control Valve  

SciTech Connect (OSTI)

This paper develops the concept of a nonreflective (or semireflective) boundary condition using the combination of a remote sensor and a control system to modulate a relief valve. The essential idea is to sense the pressure change at a remote location and then to use the measured data to adjust the opening of an active control valve at the end of the line to eliminate or attenuate the wave reflections at the valve, thus controlling system transient pressures. This novel idea is shown here through numerical simulation to have considerable potential for transient protection. Using this model, wave reflections and resonance can be effectively eliminated for frictionless pipelines or initial no-flow conditions and can be better controlled in more realistic pipelines for a range of transient disturbances. In addition, the features of even-order harmonics and nonreflective boundary conditions during steady oscillation, obtained through time domain transient analysis, are verified by hydraulic impedance analysis in the frequency domain.

Zhang, Qin Fen [ORNL] [ORNL; Karney, Professor Byran W. [University of Toronto, Canada] [University of Toronto, Canada; Pejovic, Dr. Stanislav [University of Toronto, Canada] [University of Toronto, Canada

2011-01-01T23:59:59.000Z

233

MOTION PLANNING CONTROL OF THE AIRPATH OF AN S.I. ENGINE WITH VALVE  

E-Print Network [OSTI]

to controlling the air mass aspirated in the cylinder. Besides, it is also desired to reduce engine pollutantMOTION PLANNING CONTROL OF THE AIRPATH OF AN S.I. ENGINE WITH VALVE TIMING ACTUATORS T. Leroy , J, France Abstract: We address the control of the airpath of a turbocharged S.I. engine equipped

Boyer, Edmond

234

Heart Valve Disease James S. Gammie, MD  

E-Print Network [OSTI]

Heart Valve Disease James S. Gammie, MD Professor and Chief Division of Cardiac Surgery University USA Source: CDC #12;#12;CARDIOTHORACIC SURGEON: A SURGEON THAT TREATS HEART AND LUNG DISEASE #12;Valvular Heart Disease: Common and Under-diagnosed 0 2 4 6 8 10 12 14 18 - 44 45 - 54 55 - 64 65 - 74 > 75

Weber, David J.

235

Dynamic Testing of Check Valves William Rahmeyer  

E-Print Network [OSTI]

the web site http://www.engineering.usu.edu/Departments/cee/Faculty/rahm/check.html INTRODUCTION The twoDynamic Testing of Check Valves William Rahmeyer Professor of Civil and Environmental Engineering rahmeyer@fs.uwrl.usu.edu http://www.engineering.usu.edu/Departments/cee/Faculty/rahm/check.html #12

Rahmeyer, William J.

236

Disc valve for sampling erosive process streams  

DOE Patents [OSTI]

This is a patent for a disc-type, four-port sampling valve for service with erosive high temperature process streams. Inserts and liners of ..cap alpha..-silicon carbide respectively, in the faceplates and in the sampling cavities, limit erosion while providing lubricity for a smooth and precise operation. 1 fig.

Mrochek, J.E.; Dinsmore, S.R.; Chandler, E.W.

1984-08-16T23:59:59.000Z

237

Microfluidic Cell Electroporation Using a Mechanical Valve  

E-Print Network [OSTI]

Microfluidic Cell Electroporation Using a Mechanical Valve Jun Wang, M. Jane Stine, and Chang Lu Center, and Bindley Bioscience Center, Purdue University, West Lafayette, Indiana 47907 A microfluidic of integrating electroporation as a unit operation in large- scale microfluidic systems with the increasing

Lu, Chang

238

NONLINEAR MAGNETIC LEVITATION OF AUTOMOTIVE ENGINE VALVES  

E-Print Network [OSTI]

NONLINEAR MAGNETIC LEVITATION OF AUTOMOTIVE ENGINE VALVES K. Peterson, J.W. Grizzle, and A.G. Stefanopoulou University of Michigan, Ann Arbor Abstract: Position regulation of a magnetic levitation the region of attraction. The effects of magnetic saturation are included in the model, and accounted

Grizzle, Jessy W.

239

Valve supporting arrangement of an internal combustion engine  

SciTech Connect (OSTI)

A supporting arrangement is described for a valve of an internal combustion engine having a valve stem portion, comprising a rigid member for supporting the stem portion of the valve for axial movement of the valve, a stamped or press-formed upper retainer connected to the upper portion of the valve stem, a lower annular retainer disposed on the rigid member and surrounding the valve stem, and a coil spring compressed between the upper and lower retainers to bias the valve in a direction to close the associated valve opening. The upper retainer has a substantially constant thickness throughout and comprises an annular collar portion having an essentially constant diameter along the length thereof with the diameter at least substantially equal to the inner diameter of the coil spring. The collar portion is coaxially disposed within an upper portion of the coil spring, an annular flange portion extending radially outwardly from the upper end of the collar portion and engaging with the upper end of the coil spring, and means for achieving a spline connection between the central portion of the retainer and the upper portion of the valve stem, and wherein the upper retainer is divided along a diameter into two identical elements which are disposed about the upper portion of the valve stem such that the radial pressure exerted by the coil spring operates to bias the identical elements into their respective positions operative to connect the upper retainer to the valve stem.

Hayashi, Y.

1986-05-27T23:59:59.000Z

240

Statistical Performance Evaluation Of Soft Seat Pressure Relief Valves  

SciTech Connect (OSTI)

Risk-based inspection methods enable estimation of the probability of failure on demand for spring-operated pressure relief valves at the United States Department of Energy's Savannah River Site in Aiken, South Carolina. This paper presents a statistical performance evaluation of soft seat spring operated pressure relief valves. These pressure relief valves are typically smaller and of lower cost than hard seat (metal to metal) pressure relief valves and can provide substantial cost savings in fluid service applications (air, gas, liquid, and steam) providing that probability of failure on demand (the probability that the pressure relief valve fails to perform its intended safety function during a potentially dangerous over pressurization) is at least as good as that for hard seat valves. The research in this paper shows that the proportion of soft seat spring operated pressure relief valves failing is the same or less than that of hard seat valves, and that for failed valves, soft seat valves typically have failure ratios of proof test pressure to set pressure less than that of hard seat valves.

Harris, Stephen P.; Gross, Robert E.

2013-03-26T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Hydraulically actuated gas exchange valve assembly and engine using same  

DOE Patents [OSTI]

An engine comprises a housing that defines a hollow piston cavity that is separated from a gas passage by a valve seat. The housing further defines a biasing hydraulic cavity and a control hydraulic cavity. A gas valve member is also included in the engine and is movable relative to the valve seat between an open position at which the hollow piston cavity is open to the gas passage and a closed position in which the hollow piston cavity is blocked from the gas passage. The gas valve member includes a ring mounted on a valve piece and a retainer positioned between the ring and the valve piece. A closing hydraulic surface is included on the gas valve member and is exposed to liquid pressure in the biasing hydraulic cavity.

Carroll, Thomas S. (Peoria, IL); Taylor, Gregory O. (Hinsdale, IL)

2002-09-03T23:59:59.000Z

242

Technical evaluation: 300 Area steam line valve accident  

SciTech Connect (OSTI)

On June 7, 1993, a journeyman power operator (JPO) was severely burned and later died as a result of the failure of a 6-in. valve that occurred when he attempted to open main steam supply (MSS) valve MSS-25 in the U-3 valve pit. The pit is located northwest of Building 331 in the 300 Area of the Hanford Site. Figure 1-1 shows a layout of the 300 Area steam piping system including the U-3 steam valve pit. Figure 1-2 shows a cutaway view of the approximately 10- by 13- by 16-ft-high valve pit with its various steam valves and connecting piping. Valve MSS-25, an 8-in. valve, is located at the bottom of the pit. The failed 6-in. valve was located at the top of the pit where it branched from the upper portion of the 8-in. line at the 8- by 8- by 6-in. tee and was then ``blanked off`` with a blind flange. The purpose of this technical evaluation was to determine the cause of the accident that led to the failure of the 6-in. valve. The probable cause for the 6-in. valve failure was determined by visual, nondestructive, and destructive examination of the failed valve and by metallurgical analysis of the fractured region of the valve. The cause of the accident was ultimately identified by correlating the observed failure mode to the most probable physical phenomenon. Thermal-hydraulic analyses, component stress analyses, and tests were performed to verify that the probable physical phenomenon could be reasonably expected to produce the failure in the valve that was observed.

Not Available

1993-08-01T23:59:59.000Z

243

Measure it, See it, Manage it: Using Real Time Data to Benchmark,Optimize, and Sustain System Energy Efficiency  

SciTech Connect (OSTI)

Even after years of training and awareness building at thestate and national level, industrial cross-cutting systems (motor-driven,steam, process heating) continue to offer significant opportunities forenergy savings. The US Department of Energy estimates these remainingsavings at more than 7 percent of all industrial energy use. This paperpresents a different approach to promoting industrial system energyefficiency -- providing plant personnel with ready access to data uponwhich to base energy management decisions.In 2005, a Del Monte Foodsfruit processing plant in Modesto, California worked with LawrenceBerkeley National Laboratory (LBNL)to specify and purchase permanentinstrumentation for monitoring their compressed air system. This work,completed as part of a demonstration project under a State TechnologiesAdvancement Collaborative (STAC) grant, was designed to demonstrate theeffectiveness of enterprise energy management (EEM), which is predicatedon the assumption that the energy efficiency of existing, cross-cuttingindustrial systems (motor-driven, steam) can be improved by providingmanagement and operating personnel with real-time data on energy use. Theinitial STAC grant provided for the installation and some initialanalyses, but did not address the larger issue of integrating these newdata into an ongoing energy management program for the compressed airsystem.The California Energy Commission (CEC) decided to support furtheranalysis to identify potential for air system optimization. Through theCEC's Energy in Agriculture Program, a compressed air system audit wasperformed by Tom Taranto to: Measure and document the system's baselineand CASE Index of present operation; Establish methods to sustain anongoing CASE Index measure of performance; Use AIRMaster+ to analyzesupply side performance as compared to the CASE Index; Identify demandside opportunities for efficiency and performance improvement; Assesssupply / demand balance and energy reduction opportunities; Evaluate thepresent air compressor control strategy and potential improvement, andCollect data to benchmark parameters for compressed air systems atsimilar facilities.This paper addresses the benefits and limitations ofboth continuous and targeted measurement in benchmarking, optimizing, andsustaining an efficient compressed air system. Included are methods usedin applying both of these measurements to a complex industrial system.Further, this paper will describe the results of these additionalanalyses and the plant response to them.

Taranto, Thomas; McKane, Aimee; Amon, Ricardo; Maulhardt, Michael

2007-07-02T23:59:59.000Z

244

Analysis of HFIR pressurizer pump overspeed transients and relief valve performance  

SciTech Connect (OSTI)

The pressurizer pump overspeed transients at the High Flux Isotope Reactor (HFIR) fall in the category of {open_quotes}increase in coolant inventory transients.{close_quotes} They are among the accident transients to be performed for Chapter 15 of the HFIR safety analysis report (SAR). The pressurizer pump speed starting to increase inadvertently to reach its maximum speed of 3,560 rpm while the reactor operates under normal conditions is the cause of this transient. Increased primary coolant system pressure due to increased pressurizer pump flow into the primary coolant head tank challenges the relief valves to open. If the relief valves do not open, increased primary coolant system pressure will challenge the integrity of the high pressure boundary. Two sets of analyses were performed to analyze the pressurizer pump overspeed transients. The purpose of the first analysis is to estimate how long it will take for the relief valves to open under different conditions and whether or not they will chatter or flutter for a considerable amount of time. The analysis estimates relief valve performance and stability using four different relief valve subsystem models. The relief valve subsystem models are not attached to the primary coolant system model. Vigorous pressure oscillations were produced in all of the computations performed as part of the first analysis. The second analysis includes new simulations of the pressurizer pump overspeed transients that were previously simulated using the RELAP5 thermal-hydraulic computer code. The HFIRSYS, High Flux Isotope Reactor System Transient Analysis computer code, was utilized for these simulations providing referable results for comparisons. The increased pressurizer pump flow due to runaway pressurizer pump speed pressurizes the primary coolant system. The assumptions were made in such a way to form constraining conditions at initiation of and during the transients to generate as high an overpressure situation as possible.

Sozer, M.C.

1992-09-11T23:59:59.000Z

245

Utility Accrual Real-Time Scheduling with Energy Bounds In this paper, we consider timeliness and energy optimization in battery-powered, dynamic  

E-Print Network [OSTI]

. An important technique used for optimizing the energy consumption of real-time embedded systems is dynamic in the physical world). Further, they are energy-critical, as they must operate on battery, with finite energy and minimizing the system's energy consumption, and not just the CPU's energy consumption. Moreover, such systems

Ravindran, Binoy

246

Scoping Study on the Safety Impact of Valve Spacing in Natural Gas Pipelines  

SciTech Connect (OSTI)

The U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration (PHMSA) is responsible for ensuring the safe, reliable, and environmentally sound operation of the nation's natural gas and hazardous liquid pipelines. Regulations adopted by PHMSA for gas pipelines are provided in 49 CFR 192, and spacing requirements for valves in gas transmission pipelines are presented in 49 CFR 192.179. The present report describes the findings of a scoping study conducted by Oak Ridge National Laboratory (ORNL) to assist PHMSA in assessing the safety impact of system valve spacing. Calculations of the pressures, temperatures, and flow velocities during a set of representative pipe depressurization transients were carried out using a one-dimensional numerical model with either ideal gas or real gas properties for the fluid. With both ideal gas and real gas properties, the high-consequence area radius for any resulting fire as defined by Stevens in GRI-00/0189 was evaluated as one measure of the pipeline safety. In the real gas case, a model for convective heat transfer from the pipe wall is included to assess the potential for shut-off valve failures due to excessively low temperatures resulting from depressurization cooling of the pipe. A discussion is also provided of some additional factors by which system valve spacing could affect overall pipeline safety. The following conclusions can be drawn from this work: (1) Using an adaptation of the Stephens hazard radius criteria, valve spacing has a negligible influence on natural gas pipeline safety for the pipeline diameter, pressure range, and valve spacings considered in this study. (2) Over the first 30 s of the transient, pipeline pressure has a far greater effect on the hazard radius calculated with the Stephens criteria than any variations in the transient flow decay profile and the average discharge rate. (3) Other factors besides the Stephens criteria, such as the longer burn time for an accidental fire, greater period of danger to emergency personnel, increased unavoidable loss of gas, and possible depressurization cooling of the shut-off valves may also be important when deciding whether a change in the required valve spacing would be beneficial from a safety standpoint. (4) The average normalized discharge rate of {lambda}{sub avg} = 0.33 assumed by Stephens in developing his safety criteria is an excellent conservative value for natural gas discharge at the pressures, valve spacings, and pipe diameter used in this study. This conclusion remains valid even when real rather than ideal gas properties are considered in the analysis. (5) Significant pipe wall cooling effects (T{sub w} < -50 F or 228 K) can extend for a mile or more upstream from the rupture point within 30 s of a break. These conditions are colder than the temperature range specifications for many valve lubricants. The length of the low-temperature zone due to this cooling effect is also essentially independent of the system shut-off valve spacing or the distance between the break and a compressor station. (6) Having more redundant shut-off valves available would reduce the probability that pipe cooling effects could interfere with isolating the broken area following a pipeline rupture accident.

Sulfredge, Charles David [ORNL

2007-07-01T23:59:59.000Z

247

Are subsurface safety valves needed in deepwater?  

SciTech Connect (OSTI)

The object of this study was to evaluate SCSSV reliability and identify a preferred configuration for subsea completions in deepwater. A system design consisting of subsea, conventional, dual-bore tree, cluster wells was selected for evaluation. The study examined inherent risks associated with six tubing retrievable SCSSV configurations. Risks were evaluated for personnel and environmental safety, and operational and financial impact of: No SCSSV; Single SCSSV; Dual operating system single SCSSV; Tandem hot/hot (both valves active) SCSSVs without lockout features; Tandem hot/hot SCSSVs with lockout features; Tandem hot/cold (one valve active, the other dormant in open position) SCSSVs with lockout features. A ``fault tree`` identifying events that could lead to deleterious incidents was used to evaluate risks. Costs and consequences associated with potential events were determined using existing industry data, and resulting calculated risks were evaluated. Recommendations were developed and compared to current regulations, and potential regulatory conflicts were identified.

Verret, A.; Hey, C.

1995-11-01T23:59:59.000Z

248

Lattice and off-lattice side chain models of protein folding: Linear time structure prediction better than 86% of optimal  

SciTech Connect (OSTI)

This paper considers the protein structure prediction problem for lattice and off-lattice protein folding models that explicitly represent side chains. Lattice models of proteins have proven extremely useful tools for reasoning about protein folding in unrestricted continuous space through analogy. This paper provides the first illustration of how rigorous algorithmic analyses of lattice models can lead to rigorous algorithmic analyses of off-lattice models. The authors consider two side chain models: a lattice model that generalizes the HP model (Dill 85) to explicitly represent side chains on the cubic lattice, and a new off-lattice model, the HP Tangent Spheres Side Chain model (HP-TSSC), that generalizes this model further by representing the backbone and side chains of proteins with tangent spheres. They describe algorithms for both of these models with mathematically guaranteed error bounds. In particular, the authors describe a linear time performance guaranteed approximation algorithm for the HP side chain model that constructs conformations whose energy is better than 865 of optimal in a face centered cubic lattice, and they demonstrate how this provides a 70% performance guarantee for the HP-TSSC model. This is the first algorithm in the literature for off-lattice protein structure prediction that has a rigorous performance guarantee. The analysis of the HP-TSSC model builds off of the work of Dancik and Hannenhalli who have developed a 16/30 approximation algorithm for the HP model on the hexagonal close packed lattice. Further, the analysis provides a mathematical methodology for transferring performance guarantees on lattices to off-lattice models. These results partially answer the open question of Karplus et al. concerning the complexity of protein folding models that include side chains.

Hart, W.E.; Istrail, S. [Sandia National Labs., Albuquerque, NM (United States). Algorithms and Discrete Mathematics Dept.

1996-08-09T23:59:59.000Z

249

Water cooling of HVDC thyristor valves  

SciTech Connect (OSTI)

It is generally accepted that water is a very effective medium to remove heat losses from any type of equipment. When used for HVDC thyristor valves, the fundamentals of electrolyte conduction and water chemistry need to be considered in the design of the cooling circuit. The characteristics of the materials used, in conjunction with high voltage stresses and circuit configuration, play an important role to assure longevity and corrosion-free performance.

Lips, H.P. (Siemens AG, Erlangen (Germany))

1994-10-01T23:59:59.000Z

250

Method and system for measuring gate valve clearances and seating force  

DOE Patents [OSTI]

Valve clearances and seating force, as well as other valve operational parameters, are determined by measuring valve stem rotation during opening and closing operations of a translatable gate valve. The magnitude of the stem rotation, and the relative difference between the stem rotation on opening and closing provides valuable data on the valve internals in a non-intrusive manner.

Casada, Donald A. (Knoxville, TN); Haynes, Howard D. (Knoxville, TN); Moyers, John C. (Oak Ridge, TN); Stewart, Brian K. (Burns, TN)

1996-01-01T23:59:59.000Z

251

Diagnostic for two-mode variable valve activation device  

DOE Patents [OSTI]

A method is provided for diagnosing a multi-mode valve train device which selectively provides high lift and low lift to a combustion valve of an internal combustion engine having a camshaft phaser actuated by an electric motor. The method includes applying a variable electric current to the electric motor to achieve a desired camshaft phaser operational mode and commanding the multi-mode valve train device to a desired valve train device operational mode selected from a high lift mode and a low lift mode. The method also includes monitoring the variable electric current and calculating a first characteristic of the parameter. The method also includes comparing the calculated first characteristic against a predetermined value of the first characteristic measured when the multi-mode valve train device is known to be in the desired valve train device operational mode.

Fedewa, Andrew M

2014-01-07T23:59:59.000Z

252

Novel 4-Way Refrigerant Reversing Valve for Heat Pumps  

SciTech Connect (OSTI)

This project is nearing completion. Since the last progress report (November, 1999), all experimental tests have been completed. Preliminary analysis shows the refrigerant pressure drops through the reversing valve were reduced by an average of about 60{percent}, when compared to traditional reversing valves. Also, the prototype reversing valve reduced the overall coefficient of performance (COP) by an average of only 0.45{percent}.

Darin W. Nutter

2000-02-17T23:59:59.000Z

253

Design and production of a hermetic bayonet isolation valve  

SciTech Connect (OSTI)

Fermilab is upgrading the Tevatron for lower temperature/higher beam energy operation. Portions of the satellite refrigeration system will operate below atmospheric pressure after the upgrade is complete. Contamination must be prevented by hermetically sealing the subatmospheric helium to air interfaces. Bayonet connections in the low pressure flow path require a reliable, leak tight isolation valve instead of the standard quarter turn ball valve. Design, development, and production of a new valve are described.

Fuerst, J.

1993-05-01T23:59:59.000Z

254

Hydrodynamic injection with pneumatic valving for microchip electrophoresis with total analyte utilization  

SciTech Connect (OSTI)

A novel hydrodynamic injector that is directly controlled by a pneumatic valve has been developed for reproducible microchip capillary electrophoresis (CE) separations. The poly(dimethylsiloxane) (PDMS) devices used for evaluation comprise a separation channel, a side channel for sample introduction, and a pneumatic valve aligned at the intersection of the channels. A low pressure (? 3 psi) applied to the sample reservoir is sufficient to drive sample into the separation channel. The rapidly actuated pneumatic valve enables injection of discrete sample plugs as small as ~100 pL for CE separation. The injection volume can be easily controlled by adjusting the intersection geometry, the solution back pressure and the valve actuation time. Sample injection could be reliably operated at different frequencies (< 0.1 Hz to >2 Hz) with good reproducibility (peak height relative standard deviation ? 3.6%) and no sampling biases associated with the conventional electrokinetic injections. The separation channel was dynamically coated with a cationic polymer, and FITC-labeled amino acids were employed to evaluate the CE separation. Highly efficient (? 7.0 103 theoretical plates for the ~2.4 cm long channel) and reproducible CE separations were obtained. The demonstrated method has numerous advantages compared with the conventional techniques, including repeatable and unbiased injections, no sample waste, high duty cycle, controllable injected sample volume, and fewer electrodes with no need for voltage switching. The prospects of implementing this injection method for coupling multidimensional separations, for multiplexing CE separations and for sample-limited bioanalyses are discussed.

Sun, Xuefei; Kelly, Ryan T.; Danielson, William F.; Agrawal, Nitin; Tang, Keqi; Smith, Richard D.

2011-04-26T23:59:59.000Z

255

Subsurface safety valve with lock-open system  

SciTech Connect (OSTI)

A well safety valve is described comprising: a housing having a bore therethrough; a valve mounted in the housing to open and close to control the flow through the bore; an operator tube in the housing for opening the valve; means in the housing for moving the operator tube in a first direction to open and hold the valve open; means in the housing for moving the operator tube in a second direction to permit the valve to close; a temporary lockout sleeve in the housing in tandem with the operator tube for temporarily holding the valve open. The operator tube and the lockout sleeve are in end-to-end contact when the lockout sleeve is inoperative and the operator tube is holding the valve open, when the operator tube and the lockout sleeve are moving simultaneously in the housing between operating positions, and when the operator tube is inoperative and the lockout sleeve is holding the valve open; and the operator tube and the lockout sleeve each having means for coupling the operator tube and the lockout sleeve with a lockout tool for moving the operator tube and the lockout sleeve simultaneously when the lockout sleeve is moved from the inoperative to an operative position holding the valve open.

Dickson, R.L.; Smith, R.R.

1986-11-25T23:59:59.000Z

256

aortic valve leaflet: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

diastolic diameter. The PDC Papaharilaou, Yannis 245 IMECE2007-42559 HIGH SPEED ROTARY PULSE WIDTH MODULATED ONOFF VALVE ? CiteSeer Summary: A key enabling technology to...

257

aortic valve leaflets: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

diastolic diameter. The PDC Papaharilaou, Yannis 245 IMECE2007-42559 HIGH SPEED ROTARY PULSE WIDTH MODULATED ONOFF VALVE ? CiteSeer Summary: A key enabling technology to...

258

aortic valve stenosis: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

diastolic diameter. The PDC Papaharilaou, Yannis 233 IMECE2007-42559 HIGH SPEED ROTARY PULSE WIDTH MODULATED ONOFF VALVE ? CiteSeer Summary: A key enabling technology to...

259

ahmed valve device: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

increased control in the device. Some existing micro-pumps and valves utilized in microfluidics involve electrical, pneumatic, and thermal actuation. However, electrical...

260

Flexible semi-transparent organic spin valve based on bathocuproine  

SciTech Connect (OSTI)

Organic semiconductors are attractive materials for advanced spintronic applications due to their long spin lifetimes and, simultaneously, their mechanical flexibility. With the aim of combining these advantages in a single device, we report on the fabrication and properties of a mechanically flexible bathocuproine-based spin valve. This organic spin device shows great stability on both electrical and magneto-transport properties upon mechanical bending at different radius (up to r?=?5?mm), while featuring long-lasting endurance (on bending over 50 times). The room-temperature magnetoresistance ratio reaches up to 3.5%, and is notably preserved under air atmosphere. The observation of spin transport at room-temperature, combined with the outstanding mechanical properties and air stability, highlights the potential of bathocuproine-based spin devices towards applications.

Sun, Xiangnan; Bedoya-Pinto, Amilcar; Llopis, Roger [CIC nanoGUNE, Tolosa Hiribidea 76, 20018 Donostia San Sebastian (Spain); Casanova, Flix; Hueso, Luis E., E-mail: l.hueso@nanogune.eu [CIC nanoGUNE, Tolosa Hiribidea 76, 20018 Donostia San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)

2014-08-25T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

MS17AM LEAK CHECKER The MS17AM is a manual valve version of the MS17AB. Since it is a manual unit, some care must be  

E-Print Network [OSTI]

. A gurgling sound will be heard, caused by the high pressure air being exhausted from the pump. 5 minutes (time needed for diffusion pump to heat up), turn on the ELECTRONICS switch. Turning from a total shut down. a. Position of Valves and Control Switches Rough Pump.......Off Rough Valve

Massey, Thomas N.

262

Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO2 Enhanced Oil Recovery Operations  

SciTech Connect (OSTI)

This project, 'Application of Time-Lapse Seismic Monitoring for the Control and Optimization of CO{sub 2} Enhanced Oil Recovery Operations', investigated the potential for monitoring CO{sub 2} floods in carbonate reservoirs through the use of standard p-wave seismic data. This primarily involved the use of 4D seismic (time lapse seismic) in an attempt to observe and map the movement of the injected CO{sub 2} through a carbonate reservoir. The differences between certain seismic attributes, such as amplitude, were used for this purpose. This technique has recently been shown to be effective in CO{sub 2} monitoring in Enhanced Oil Recovery (EOR) projects, such as Weyborne. This study was conducted in the Charlton 30/31 field in the northern Michigan Basin, which is a Silurian pinnacle reef that completed its primary production in 1997 and was scheduled for enhanced oil recovery using injected CO{sub 2}. Prior to injection an initial 'Base' 3D survey was obtained over the field and was then processed and interpreted. CO{sub 2} injection within the main portion of the reef was conducted intermittently during 13 months starting in August 2005. During this time, 29,000 tons of CO{sub 2} was injected into the Guelph formation, historically known as the Niagaran Brown formation. By September 2006, the reservoir pressure within the reef had risen to approximately 2000 lbs and oil and water production from the one producing well within the field had increased significantly. The determination of the reservoir's porosity distribution, a critical aspect of reservoir characterization and simulation, proved to be a significant portion of this project. In order to relate the differences observed between the seismic attributes seen on the multiple 3D seismic surveys and the actual location of the CO{sub 2}, a predictive reservoir simulation model was developed based on seismic attributes obtained from the base 3D seismic survey and available well data. This simulation predicted that the CO{sub 2} injected into the reef would remain in the northern portion of the field. Two new wells, the State Charlton 4-30 and the Larsen 3-31, were drilled into the field in 2006 and 2008 respectively and supported this assessment. A second (or 'Monitor') 3D seismic survey was acquired during September 2007 over most of the field and duplicated the first (Base) survey, as much as possible. However, as the simulation and new well data available at that time indicated that the CO{sub 2} was concentrated in the northern portion of the field, the second seismic survey was not acquired over the extreme southern end of the area covered by the original (or Base) 3D survey. Basic processing was performed on the second 3D seismic survey and, finally, 4D processing methods were applied to both the Base and the Monitor surveys. In addition to this 3D data, a shear wave seismic data set was obtained at the same time. Interpretation of the 4D seismic data indicated that a significant amplitude change, not attributable to differences in acquisition or processing, existed at the locations within the reef predicted by the reservoir simulation. The reservoir simulation was based on the porosity distribution obtained from seismic attributes from the Base 3D survey. Using this validated reservoir simulation the location of oil within the reef at the time the Monitor survey was obtained and recommendations made for the drilling of additional EOR wells. The economic impact of this project has been estimated in terms of both enhanced oil recovery and CO{sub 2} sequestration potential. In the northern Michigan Basin alone, the Niagaran reef play is comprised of over 700 Niagaran reefs with reservoirs already depleted by primary production. Potentially there is over 1 billion bbls of oil (original oil in place minus primary recovery) remains in the reefs in Michigan, much of which could be more efficiently mobilized utilizing techniques similar to those employed in this study.

Brian Toelle

2008-11-30T23:59:59.000Z

263

Numerical Investigation of the Performance of Three Hinge Designs of Bileaflet Mechanical Heart Valves  

E-Print Network [OSTI]

parameters on bilea?et mechanical heart valve ?ow dynamics.J. Heart Valve Dis. 18:535545, 2009. Gross, J. M. , M. C.two bilea?et mechanical heart valves under aortic and mitral

Simon, Hlne A.; Ge, Liang; Sotiropoulos, Fotis; Yoganathan, Ajit P.

2010-01-01T23:59:59.000Z

264

E-Print Network 3.0 - air operated valve Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

.5 mm in dia- meter. To create an inlet for air into the pneumatic valve, we used polyethylene tubing... the pneumatic valve, we connected the tubing of the valve ... Source:...

265

Design of a gas force simulator for the MIT Electromechanical Valve Drive project  

E-Print Network [OSTI]

The MIT electromechanical Valve Drive (EMVD) is a continuously variable valve actuation device for an automotive internal combustion engine. Current experimentation of the EMVD has been limited to intake valve events. When ...

Otten, James S. (James Stewart)

2006-01-01T23:59:59.000Z

266

System and method for controlling engine knock using electro-hydraulic valve actuation  

DOE Patents [OSTI]

A control system for an engine includes a knock control module and a valve control module. The knock control module adjusts a period that one or more of an intake valve and an exhaust valve of a cylinder are open based on engine knock corresponding to the cylinder. The valve control module, based on the adjusted period, controls the one or more of the intake valve and the exhaust valve using one or more hydraulic actuators.

Brennan, Daniel G

2013-12-10T23:59:59.000Z

267

Impact of Variable Valve Timing on Low Temperature Combustion...  

Broader source: Energy.gov (indexed) [DOE]

and Combustion Effects of VVA Ignition Temperature and Ignition Delay Soot Chemistry Combine effects with PCCI Extension of LTC Operation Summary Acknowledgements and...

268

Impact of Variable Valve Timing on Low Temperature Combustion | Department  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensionalthe U.S. Department-2023 Idaho4Fuel Consumption Solutionsof

269

Corrosion in HVDC valve cooling systems  

SciTech Connect (OSTI)

Stainless steel couplings in the main cooling water pipes of HVDC thyristor valves have been in use since 1983, with an overall satisfactory behavior. However, some water leakage due to corrosion below the sealing O-rings of the couplings was observed during 1992. An extensive investigation and follow-up worldwide showed a direct correlation between water quality and the corrosion rate of the stainless steel couplings. Recommendations are given about actions to be taken in order to maintain a long lifetime for the fine water systems.

Jackson, P.O.; Abrahamsson, B.; Gustavsson, D.; Igetoft, L.

1997-04-01T23:59:59.000Z

270

Nuclear-radiation-actuated valve. [Patent application; for increasing coolant flow to blanket  

DOE Patents [OSTI]

The present invention relates to a breeder reactor blanket fuel assembly coolant system valve which increases coolant flow to the blanket fuel assembly to minimize long-term temperature increases caused by fission of fissile fuel created from fertile fuel through operation of the breeder reactor. The valve has a valve first part (such as a valve rod with piston) and a valve second part (such as a valve tube surrounding the valve rod, with the valve tube having side slots surrounding the piston). Both valve parts have known nuclear radiation swelling characteristics. The valve's first part is positioned to receive nuclear radiation from the nuclear reactor's fuel region. The valve's second part is positioned so that its nuclear radiation induced swelling is different from that of the valve's first part. The valve's second part also is positioned so that the valve's first and second parts create a valve orifice which changes in size due to the different nuclear radiation caused swelling of the valve's first part compared to the valve's second part. The valve may be used in a nuclear reactor's core coolant system.

Christiansen, D.W.; Schively, D.P.

1982-01-19T23:59:59.000Z

271

E-Print Network 3.0 - aortic valve bioprosthesis Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of Biomechanics 34 (2001) 12791289 A nonlinear anisotropic model for porcine aortic heart valves Summary: of porcine aortic valve leaflet has potentially significant effects on...

272

E-Print Network 3.0 - aortic valve insufficiency Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

insufficiency Page: << < 1 2 3 4 5 > >> 1 Interaction between the mitral and aortic heart valve Summary: Interaction between the mitral and aortic heart valve an experimental...

273

E-Print Network 3.0 - aortic valve reconstruction Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

reconstruction Page: << < 1 2 3 4 5 > >> 1 Interaction between the mitral and aortic heart valve Summary: Interaction between the mitral and aortic heart valve an experimental...

274

E-Print Network 3.0 - aortic disc valve Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hannover Collection: Biology and Medicine 2 Interaction between the mitral and aortic heart valve Summary: Interaction between the mitral and aortic heart valve an experimental...

275

E-Print Network 3.0 - aortic valve prostheses Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

... Source: Collection: Engineering 2 Interaction between the mitral and aortic heart valve Summary: and aortic valve prostheses as well as give directions for improvement...

276

E-Print Network 3.0 - aortic valve morphology Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Toronto Collection: Engineering ; Biology and Medicine 2 Mechanobiology of the Aortic Heart Valve Jonathan T. Butcher1 Summary: Review: Mechanobiology of the Aortic Heart Valve...

277

E-Print Network 3.0 - aortic valve interstitial Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Toronto Collection: Engineering ; Biology and Medicine 2 Mechanobiology of the Aortic Heart Valve Jonathan T. Butcher1 Summary: Review: Mechanobiology of the Aortic Heart Valve...

278

Energy Savings Opportunities in Control Valves  

SciTech Connect (OSTI)

This is one in a series of tip sheets to help manufacturers optimize their industrial pumping systems.

Not Available

2007-03-01T23:59:59.000Z

279

Nonlinear Control for Magnetic Levitation of Automotive Engine Valves  

E-Print Network [OSTI]

1 Nonlinear Control for Magnetic Levitation of Automotive Engine Valves Katherine Peterson, Member of a magnetic levitation device is achieved through a control Lyapunov function (CLF) feedback design for and implemented on an electromagnetic valve actuator for use in automotive engines, the control methodology

Grizzle, Jessy W.

280

Analysis of Cardiac Micro-Acceleration Signals for the Estimation of Systolic and Diastolic Time Intervals in Cardiac Resynchronization Therapy  

E-Print Network [OSTI]

error and coefficient stability. Models for mitral valve closing, aor- tic valve closing and opening, fitted between CMA features and echo timings, were eval- uated with their correlation coefficient, model instants showed satisfactory results, whereas the estimation of the opening instant of the mitral valve

Boyer, Edmond

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Negative Valve Overlap Reforming Chemistry in Low-Oxygen Environments  

SciTech Connect (OSTI)

Fuel injection into the negative valve overlap (NVO) period is a common method for controlling combustion phasing in homogeneous charge compression ignition (HCCI) and other forms of advanced combustion. When fuel is injected into O2-deficient NVO conditions, a portion of the fuel can be converted to products containing significant levels of H2 and CO. Additionally, other short chain hydrocarbons are produced by means of thermal cracking, water-gas shift, and partial oxidation reactions. The present study experimentally investigates the fuel reforming chemistry that occurs during NVO. To this end, two very different experimental facilities are utilized and their results are compared. One facility is located at Oak Ridge National Laboratory, which uses a custom research engine cycle developed to isolate the NVO event from main combustion, allowing a steady stream of NVO reformate to be exhausted from the engine and chemically analyzed. The other experimental facility, located at Sandia National Laboratories, uses a dump valve to capture the exhaust from a single NVO event for analysis. Results from the two experiments are in excellent trend-wise agreement and indicate that the reforming process under low-O2 conditions produces substantial concentrations of H2, CO, methane, and other short-chain hydrocarbon species. The concentration of these species is found to be strongly dependent on fuel injection timing and injected fuel type, with weaker dependencies on NVO duration and initial temperature, indicating that NVO reforming is kinetically slow. Further, NVO reforming does not require a large energy input from the engine, meaning that it is not thermodynamically expensive. The implications of these results on HCCI and other forms of combustion are discussed in detail.

Szybist, James P [ORNL] [ORNL; Steeper, Richard R. [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Splitter, Derek A [ORNL] [ORNL; Kalaskar, Vickey B [ORNL] [ORNL; Pihl, Josh A [ORNL] [ORNL; Daw, C Stuart [ORNL] [ORNL

2014-01-01T23:59:59.000Z

282

Processing of prosthetic heart valve sounds for classification. Revision 1  

SciTech Connect (OSTI)

People with serious heart conditions have had their expected life span extended considerably with the development of the prosthetic heart valve especially with the great strides made in valve design. Even though the designs are extremely reliable, the valves are mechanical and operating continuously over a long period, therefore, structural failures can occur due to fatigue. Measuring heart sounds non-invasively in a noisy environment puts more demands on the signal processing to extract the desired signals from the noise. In this paper the authors discuss acoustical signal processing techniques developed to process noisy heart valve sounds measured by a sensitive, surface contact microphone and used for the eventual classification of the valve.

Candy, J.V.; Jones, H.E.

1994-04-01T23:59:59.000Z

283

Optimization Online - Optimal synthesis in the Reeds and Shepp ...  

E-Print Network [OSTI]

Sep 9, 2011 ... Keywords: Reeds and Shepp car, time-optimal problem, Pontryagin Maximum Principle, reachability sets, optimal synthesis. Category 1:...

Andrey Dmitruk

2011-09-09T23:59:59.000Z

284

Processing of Prosthetic Heart Valve Sounds from Anechoic Tank Measurements  

SciTech Connect (OSTI)

People with serious cardiac problems have had their life span extended with the development of the prosthetic heart valve. However, the valves operate continuously at approximately 39 million cycles per year and are therefore subject to structural failures either by faulty design or material fatigue. The development of a non-invasive technique using an acoustic contact microphone and sophisticated signal processing techniques has been proposed and demonstrated on limited data sets. In this paper we discuss an extension of the techniques to perform the heart valve tests in an anechoic like. Here the objective is to extract a ''pure'' sound or equivalently the acoustical vibration response of the prosthetic valves in a quiet environment. The goal is to demonstrate that there clearly exist differences between values which have a specific mechanical defect known as single leg separation (SLS) and non-defective valves known as intact (INT). We discuss the signal processing and results of anechoic acoustic measurements on 50 prosthetic valves in the tank. Finally, we show the results of the individual runs for each valve, point out any of the meaningful features that could be used to distinguish the SLS from INT and summarize the experiments.

Candy, J V; Meyer, A W

2001-03-20T23:59:59.000Z

285

System for remotely servicing a top loading captive ball valve  

DOE Patents [OSTI]

An attachment for facilitating servicing of a valve, the valve including: an assembly composed of a valve seat defining a flow path, a flow control member movable relative to the valve seat for blocking or unblocking the valve seat, and a control device including a stem coupled to the flow control member and operable for moving the flow control member relative to the valve seat; a housing for receiving the assembly, the housing having an opening via which the assembly can be removed from, and installed in, the housing, and the housing having a plurality of threaded studs which surround the opening and project away from the housing; a valve housing cover for closing and sealing the opening in the housing, the cover having a first bore for passage of the stem of the control device when the assembly is installed in the housing and a plurality of second bores each located for passage of a respective stud when the cover closes the opening in the housing. A plurality of threaded nuts are engageable with the studs for securing the cover to the housing when the cover closes the opening in the housing, wherein the attachment comprises: a plurality of nut guide devices removable from the housing and each operatively associated with a respective stud for retaining a respective nut and guiding the respective nut into alignment with the respective stud to enable the respective nut to be rotated into engagement with the respective stud; and aligning the nut guide devices with the studs.

Berry, Stephen M. (Idaho Falls, ID); Porter, Matthew L. (North Potomac, MD)

1996-01-01T23:59:59.000Z

286

In-line real time air monitor  

DOE Patents [OSTI]

An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds.

Wise, Marcus B. (Kingston, TN); Thompson, Cyril V. (Knoxville, TN)

1998-01-01T23:59:59.000Z

287

In-line real time air monitor  

DOE Patents [OSTI]

An in-line gas monitor capable of accurate gas composition analysis in a continuous real time manner even under strong applied vacuum conditions operates by mixing an air sample with helium forming a sample gas in two complementary sample loops embedded in a manifold which includes two pairs of 3-way solenoid valves. The sample gas is then analyzed in an ion trap mass spectrometer on a continuous basis. Two valve drivers actuate the two pairs of 3-way valves in a reciprocating fashion, so that there is always flow through the in-line gas monitor via one or the other of the sample loops. The duty cycle for the two pairs of 3-way valves is varied by tuning the two valve drivers to a duty cycle typically between 0.2 to 0.7 seconds. 3 figs.

Wise, M.B.; Thompson, C.V.

1998-07-14T23:59:59.000Z

288

Analysis of a Third-Generation Princeton Tri-leaflet Mechanical Heart Valve  

E-Print Network [OSTI]

Analysis of a Third-Generation Princeton Tri-leaflet Mechanical Heart Valve Michael Hsu Advisor heart valve · Static analysis of leaflet under uniform pressure of 10 MPa Summer Objectives · Find Heart valve disease · Over 5 million affected · Over 225,000 valve- replacement surgeries performed

Petta, Jason

289

Turbo-generator control with variable valve actuation  

DOE Patents [OSTI]

An internal combustion engine incorporating a turbo-generator and one or more variably activated exhaust valves. The exhaust valves are adapted to variably release exhaust gases from a combustion cylinder during a combustion cycle to an exhaust system. The turbo-generator is adapted to receive exhaust gases from the exhaust system and rotationally harness energy therefrom to produce electrical power. A controller is adapted to command the exhaust valve to variably open in response to a desired output for the turbo-generator.

Vuk, Carl T. (Denver, IA)

2011-02-22T23:59:59.000Z

290

Walking, running, and resting under time, distance, and average speed constraints: Optimality of walk-run-rest mixtures  

E-Print Network [OSTI]

in a more ecological (non-treadmill) setting. We asked subjects to travel a given distance overground to go from your house to the bus stop and have very little time to do so. You would likely run the whole

Srinivasan, Manoj

291

PCV valve flutter : vibration characterization through pressure and flow  

E-Print Network [OSTI]

A Positive Crankcase Ventilation, or PCV, valve is required by internal combustion engines in order to regulate the flow of blow-by gases out of the crankcase and into the intake air stream. Fluctuations in the pressure ...

Gomez, Nicasio

2005-01-01T23:59:59.000Z

292

Design of an electronically-actuated gas lift safety valve  

E-Print Network [OSTI]

Gas lift valves are widely used in oil production fields to pump recycled gas and nitrogen into the production tubing, to sustain production by aerating the oil and lifting it to the ground or sea surface. Today's industry ...

Yu, Changkuan, S.M. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

293

Spin-valve photodiode Ian Appelbaum,a)  

E-Print Network [OSTI]

Spin-valve photodiode Ian Appelbaum,a) D. J. Monsma, K. J. Russell, V. Narayanamurti, and C. M using internal photoemission to generate hot electrons in magnetic multilayer Schottky photodiodes

Russell, Kasey

294

Failure Mode and Sensitivity Analysis of Gas Lift Valves  

E-Print Network [OSTI]

Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valves. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure ...

Gilbertson, Eric W.

295

Friction and Wear Reduction in Diesel Engine Valve Trains  

Broader source: Energy.gov (indexed) [DOE]

commercial exhaust valve * Surface damage from 20,000 impacts displays micro-welding, plastic deformation, and transfer. 9 Managed by UT-Battelle for the Department of Energy...

296

Mechanisms of Oxidation-Enhanced Wear in Diesel Exhaust Valves...  

Broader source: Energy.gov (indexed) [DOE]

of wear oxidation microstructures of alloys Fe-, Ni-, Co-alloys h T h i h v Combined plastic deformation, wear, and oxidation on both valve and seat surfaces 6 Managed by...

297

International Environmental Agreements: Emissions trade, safety valves and escape clauses  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5 Escape clauses versus safety valves 13 6 Review of "standard model" of IEAs 14 6.1 Dynamics The effect of emissions trade on IEA participation 17 7.1 Ex ante heterogenous countries

Karp, Larry S.

298

Energy Savings Potential of Process Control Valve Replacement  

E-Print Network [OSTI]

candidates for savings. A feasibility study of retrofitting a pipeline flow control system, currently operating with a constant speed pump and differential producing, modulating control valve, with a variable speed drive is presented. This case study...

Holzenthal, L. Jr.

299

Electric actuation of a surface controlled subsea safety valve  

E-Print Network [OSTI]

to the conversion of many components from hydraulic operation to electric. Therefore, it is the purpose of this report to detail and propose an engineering solution to the electrical conversion of a surface controlled subsea safety valve (SCSSV). Preliminary...

Bartlett, Timothy Joseph

2013-02-22T23:59:59.000Z

300

Automated auscultation : using acoustic features to diagnose mitral valve prolapse  

E-Print Network [OSTI]

During annual physical examinations, a primary-care physician listens to the heart using a stethoscope to assess the condition of the heart muscle and valves. This process, termed cardiac auscultation, is the primary means ...

Jung, Marcia Yeojin, 1982-

2004-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Nonlinear springs with applications to flow regulation valves and mechanisms  

E-Print Network [OSTI]

This thesis focuses on the application of nonlinear springs for fluid flow control valves where geometric constraints, or fabrication technologies, limit the use of available solutions. Types of existing nonlinear springs ...

Freeman, David Calvin

2008-01-01T23:59:59.000Z

302

Replace Pressure-Reducing Valves with Backpressure Turbogenerators  

SciTech Connect (OSTI)

This revised ITP steam tip sheet on replacing pressure-reducing valves provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

303

Optimization of high-order harmonic generation by genetic algorithm and wavelet time-frequency analysis of quantum dipole emission  

E-Print Network [OSTI]

-order har- monic generation ~HHG! of orders as high as 300 has been observed @5,6#, with photon energies in excess of 500 eV. A novel concept of intra-atomic phase matching has been recently introduced, allowing the enhancement of the inten- sity of a..., as shown in Fig. 2, the major time domain contributing to the total har- monic intensity is the central part of the laser pulse with significant field intensity ~for example, between 24 to 14 optical cycles!. Beyond this central time regime, the har- monic...

Chu, Xi; Chu, Shih-I

2001-07-13T23:59:59.000Z

304

Signal processing of Shiley heart valve data for fracture detection  

SciTech Connect (OSTI)

Given digital acoustic data emanating from the heart sounds of the beating heart measured from laboratory sheep with implanted Bjoerk-Shiley Convexo-Concave heart valves, it is possible to detect and extract the opening and closing heart beats from the data. Once extracted, spectral or other information can then obtained from the heartbeats and passed on to feature extraction algorithms, neutral networks, or pattern recognizers so that the valve condition, either fractured or intact, may be determined.

Mullenhoff, C.

1993-04-01T23:59:59.000Z

305

Signal processing of Shiley heart valve data for fracture detection  

SciTech Connect (OSTI)

Given digital acoustic data emanating from the heart sounds of the beating heart measured from laboratory sheep with implanted Bjoerk-Shiley Convexo-Concave heart valves, it is possible to detect and extract the opening and closing heart beats from the data. Once extracted, spectral or other information can then obtained from the heartbeats and passed on to feature extraction algorithms, neural networks, or pattern recognizers so that the valve condition, either fractured or intact, may be determined.

Mullenhoff, C.

1993-09-01T23:59:59.000Z

306

Expanding Robust HCCI Operation with Advanced Valve and Fuel Control Technologies  

SciTech Connect (OSTI)

Delphi Automotive Systems and ORNL established this CRADA to advance the commercialization potential of the homogeneous charge compression ignition (HCCI) advanced combustion strategy for gasoline engine platforms. HCCI combustion has been shown by others to produce high diesel-like efficiency on a gasoline engine platform while simultaneously producing low NOX and particulate matter emissions. However, the commercialization barriers that face HCCI combustion are significant, with requirements for a more active engine control system, likely with next-cycle closed-loop feedback control, and with advanced valve train technologies to enable negative valve overlap conditions. In the partnership between Delphi and ORNL, each organization brought a unique and complementary set of skills to the project. Delphi has made a number of breakthroughs with production-intent valve train technologies and controls in recent years to make a part time production-intent HCCI engine plausible. ORNL has extensive knowledge and expertise with HCCI combustion, and also has a versatile research engine with hydraulic valve actuation (HVA) that is useful for guiding production of a cam-based HCCI system. Partnering these knowledge bases and capabilities was essential towards making progress to better understand HCCI combustion and the commercialization barriers that it faces. ORNL and Delphi maintained strong collaboration throughout the project. Meetings were held regularly, with additional reports, presentations, and meetings as necessary to maintain progress. Delphi provided guidance to ORNL regarding operational strategies to investigate on their single-cylinder research engine with HVA and data from their experimental multi-cylinder engine for modeling. ORNL provided single-cylinder engine data and modeling results.

Szybist, J. P. [Oak Ridge National Lab., Oak Ridge, TN (United States); Confer, K. [Delphi Automotive Systems (United States)

2012-09-11T23:59:59.000Z

307

System for remotely servicing a top loading captive ball valve  

DOE Patents [OSTI]

An attachment for facilitating servicing of a valve is disclosed including: an assembly composed of a valve seat defining a flow path, a flow control member movable relative to the valve seat for blocking or unblocking the valve seat, and a control device including a stem coupled to the flow control member and operable for moving the flow control member relative to the valve seat; a housing for receiving the assembly, the housing having an opening via which the assembly can be removed from, and installed in, the housing, and the housing having a plurality of threaded studs which surround the opening and project away from the housing; a valve housing cover for closing and sealing the opening in the housing, the cover having a first bore for passage of the stem of the control device when the assembly is installed in the housing and a plurality of second bores each located for passage of a respective stud when the cover closes the opening in the housing. A plurality of threaded nuts are engageable with the studs for securing the cover to the housing when the cover closes the opening in the housing, wherein the attachment comprises: a plurality of nut guide devices removable from the housing and each operatively associated with a respective stud for retaining a respective nut and guiding the respective nut into alignment with the respective stud to enable the respective nut to be rotated into engagement with the respective stud; and aligning the nut guide devices with the studs. 7 figs.

Berry, S.M.; Porter, M.L.

1996-06-25T23:59:59.000Z

308

Valving for controlling a fluid-driven reciprocating apparatus  

DOE Patents [OSTI]

A pair of control valve assemblies for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve assembly is switched by a pressure signal depending on the state of its counterpart's piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. Each of the valve assemblies uses an intake-exhaust valve and a signal valve with the signal valve of one pump being connected to be pressure responsive to the piston of the opposite cylinder or pump.

Whitehead, John C. (Davis, CA)

1995-01-01T23:59:59.000Z

309

Valving for controlling a fluid-driven reciprocating apparatus  

DOE Patents [OSTI]

A pair of control valve assemblies is described for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve assembly is switched by a pressure signal depending on the state of its counterpart`s piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. Each of the valve assemblies uses an intake-exhaust valve and a signal valve with the signal valve of one pump being connected to be pressure responsive to the piston of the opposite cylinder or pump. 15 figs.

Whitehead, J.C.

1995-06-27T23:59:59.000Z

310

Gas lift valve failure mode analysis and the design of a thermally-actuated positive-locking safety valve  

E-Print Network [OSTI]

Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valves. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure ...

Gilbertson, Eric (Eric W.)

2010-01-01T23:59:59.000Z

311

Extreme Optimization Announcements  

E-Print Network [OSTI]

Extreme Optimization Announcements Assignment 3 due tomorrow @ 5pm. No late days on Extreme, we will hold extra office hours during regular section times. #12;Extreme Optimization Extreme University Fall 2014 #12;Extreme Optimization The radiotherapy problem Saving Lives: Radiotherapy Radiation

Chen, Yiling

312

Monovalve with integrated fuel injector and port control valve, and engine using same  

DOE Patents [OSTI]

An engine includes an engine casing that defines a hollow piston cavity separated from an exhaust passage and an intake passage by a valve seat. A gas exchange valve member is positioned adjacent the valve seat and is moveable between an open position and a closed position. The gas exchange valve member also defines an opening that opens into the hollow piston cavity. A needle valve member is positioned in the gas exchange valve member adjacent a nozzle outlet and is moveable between an inject position and a blocked position. A port control valve member, which has a hydraulic surface, is mounted around the gas exchange valve member and moveable between an intake position and an exhaust position. A pilot valve is moveable between a first position at which the port control hydraulic surface is exposed to a source of high pressure fluid, and a second position at which the port control hydraulic surface is exposed to a source of low pressure fluid.

Milam, David M. (Metamora, IL)

2001-11-06T23:59:59.000Z

313

Engine including hydraulically actuated valvetrain and method of valve overlap control  

DOE Patents [OSTI]

An exhaust valve control method may include displacing an exhaust valve in communication with the combustion chamber of an engine to an open position using a hydraulic exhaust valve actuation system and returning the exhaust valve to a closed position using the hydraulic exhaust valve actuation assembly. During closing, the exhaust valve may be displaced for a first duration from the open position to an intermediate closing position at a first velocity by operating the hydraulic exhaust valve actuation assembly in a first mode. The exhaust valve may be displaced for a second duration greater than the first duration from the intermediate closing position to a fully closed position at a second velocity at least eighty percent less than the first velocity by operating the hydraulic exhaust valve actuation assembly in a second mode.

Cowgill, Joel (White Lake, MI)

2012-05-08T23:59:59.000Z

314

A FEASIBILITY AND OPTIMIZATION STUDY TO DETERMINE COOLING TIME AND BURNUP OF ADVANCED TEST REACTOR FUELS USING A NONDESTRUCTIVE TECHNIQUE  

SciTech Connect (OSTI)

The goal of this study presented is to determine the best available non-destructive technique necessary to collect validation data as well as to determine burn-up and cooling time of the fuel elements onsite at the Advanced Test Reactor (ATR) canal. This study makes a recommendation of the viability of implementing a permanent fuel scanning system at the ATR canal and leads3 to the full design of a permanent fuel scan system. The study consisted at first in determining if it was possible and which equipment was necessary to collect useful spectra from ATR fuel elements at the canal adjacent to the reactor. Once it was establish that useful spectra can be obtained at the ATR canal the next step was to determine which detector and which configuration was better suited to predict burnup and cooling time of fuel elements non-destructively. Three different detectors of High Purity Germanium (HPGe), Lanthanum Bromide (LaBr3), and High Pressure Xenon (HPXe) in two system configurations of above and below the water pool were used during the study. The data collected and analyzed was used to create burnup and cooling time calibration prediction curves for ATR fuel. The next stage of the study was to determine which of the three detectors tested was better suited for the permanent system. From spectra taken and the calibration curves obtained, it was determined that although the HPGe detector yielded better results, a detector that could better withstand the harsh environment of the ATR canal was needed. The in-situ nature of the measurements required a rugged fuel scanning system, low in maintenance and easy to control system. Based on the ATR canal feasibility measurements and calibration results it was determined that the LaBr3 detector was the best alternative for canal in-situ measurements; however in order to enhance the quality of the spectra collected using this scintillator a deconvolution method was developed. Following the development of the deconvolution method for ATR applications the technique was tested using one-isotope, multi-isotope and fuel simulated sources. Burnup calibrations were perfomed using convoluted and deconvoluted data. The calibrations results showed burnup prediction by this method improves using deconvolution. The final stage of the deconvolution method development was to perform an irradiation experiment in order to create a surrogate fuel source to test the deconvolution method using experimental data. A conceptual design of the fuel scan system is path forward using the rugged LaBr3 detector in an above the water configuration and deconvolution algorithms.

Jorge Navarro

2013-12-01T23:59:59.000Z

315

Optimization Online  

E-Print Network [OSTI]

Optimization Online is a repository of e-prints about optimization and related topics. Submissions to Optimization Online are moderated by a team of volunteer

316

System and method for controlling hydraulic pressure in electro-hydraulic valve actuation systems  

DOE Patents [OSTI]

A control system for an engine includes a first lift control module and a second lift control module. The first lift control module increases lift of M valves of the engine to a predetermined valve lift during a period before disabling or re-enabling N valves of the engine. The second lift control module decreases the lift of the M valves to a desired valve lift during a period after enabling or re-enabling the N valves of the engine, wherein N and M are integers greater than or equal to one.

Brennan, Daniel G; Marriott, Craig D; Cowgill, Joel; Wiles, Matthew A; Patton, Kenneth James

2014-09-23T23:59:59.000Z

317

Reduced-impact sliding pressure control valve for pneumatic hammer drill  

DOE Patents [OSTI]

A method and means of minimizing the effect of elastic valve recoil in impact applications, such as percussive drilling, where sliding spool valves used inside the percussive device are subject to poor positioning control due to elastic recoil effects experienced when the valve impacts a stroke limiting surface. The improved valve design reduces the reflected velocity of the valve by using either an energy damping material, or a valve assembly with internal damping built-in, to dissipate the compression stress wave produced during impact.

Polsky, Yarom (Oak Ridge, TN); Grubelich, Mark C. (Albuquerque, NM); Vaughn, Mark R. (Albuquerque, NM)

2012-05-15T23:59:59.000Z

318

Engine control system having pressure-based timing  

DOE Patents [OSTI]

A control system for an engine having a first cylinder and a second cylinder is disclosed having a first engine valve movable to regulate a fluid flow of the first cylinder and a first actuator associated with the first engine valve. The control system also has a second engine valve movable to regulate a fluid flow of the second cylinder and a sensor configured to generate a signal indicative of a pressure within the first cylinder. The control system also has a controller that is in communication with the first actuator and the sensor. The controller is configured to compare the pressure within the first cylinder with a desired pressure and selectively regulate the first actuator to adjust a timing of the first engine valve independently of the timing of the second engine valve based on the comparison.

Willi, Martin L. (Dunlap, IL); Fiveland, Scott B. (Metamora, IL); Montgomery, David T. (Edelstein, IL); Gong, Weidong (Dunlap, IL)

2011-10-04T23:59:59.000Z

319

Measuring while drilling apparatus mud pressure signal valve  

SciTech Connect (OSTI)

This patent describes a measurement while drilling system for borehole drilling having a downhole instrument connectable in a drill string of a rotary drilling rig including apparatus to sense geological and geophysical parameters and a valve apparatus to pulse modulate drilling fluid flowing in the drill string. A surface apparatus is connected to a drilling fluid flow conductor for extracting intelligence carrying information from the modulated drilling fluid. An improved valve apparatus is described comprising: (a) a drilling fluid flow pulse modulating pressure pulse valve member longitudinally, movably mounted in a body member and movable from a retracted position substantially removed from the drilling fluid flow and an extended position disposed at least partially within the drilling fluid flow thereby temporarily restricting drilling fluid flow within the drill string; and (b) the pulse valve member is a tubular member having a lower end portion displaceable from the body member into the drilling fluid and an upper end portion with opposed fluid pressure force areas thereon being in fluid communication with the drilling fluid flow such that forces due to the drilling fluid acting on the pressure pulse valve member are balanced in a longitudinal direction.

Peppers, J.M.; Shaikh, F.A.

1986-12-09T23:59:59.000Z

320

Simulation of a suite of generic long-pulse neutron instruments to optimize the time structure of the European Spallation Source  

SciTech Connect (OSTI)

We here describe the result of simulations of 15 generic neutron instruments for the long-pulsed European Spallation Source. All instruments have been simulated for 20 different settings of the source time structure, corresponding to pulse lengths between 1 ms and 2 ms; and repetition frequencies between 10 Hz and 25 Hz. The relative change in performance with time structure is given for each instrument, and an unweighted average is calculated. The performance of the instrument suite is proportional to (a) the peak flux and (b) the duty cycle to a power of approximately 0.3. This information is an important input to determining the best accelerator parameters. In addition, we find that in our simple guide systems, most neutrons reaching the sample originate from the central 3-5 cm of the moderator. This result can be used as an input in later optimization of the moderator design. We discuss the relevance and validity of defining a single figure-of-merit for a full facility and compare with evaluations of the individual instrument classes.

Lefmann, Kim; Kleno, Kaspar H.; Holm, Sonja L.; Sales, Morten [Nanoscience and eScience Centers, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen O (Denmark); Danish Workpackage for the ESS Design Update Phase, Universitetsparken 5, 2100 Copenhagen O (Denmark); Birk, Jonas Okkels [Nanoscience and eScience Centers, Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen O (Denmark); Danish Workpackage for the ESS Design Update Phase, Universitetsparken 5, 2100 Copenhagen O (Denmark); Laboratory for Quantum Magnetism, Ecole Polytecnique Federale de Lausanne (EPFL), 1015 Lausanne (Switzerland); Hansen, Britt R.; Knudsen, Erik; Willendrup, Peter K. [Institute of Physics, Technical University of Denmark, 2800 Lyngby (Denmark); Danish Workpackage for the ESS Design Update Phase, 2800 Lyngby (Denmark); Lieutenant, Klaus [Institute for Energy Technology, Instituttveien 18, 2007 Kjeller (Norway); Helmholtz Center for Energy and Materials, Hahn-Meitner Platz, 14109 Berlin (Germany); German Work Package for the ESS Design Update, Hahn-Meitner Platz, 14109 Berlin (Germany); Moos, Lars von [Department of Energy Conversion and Storage, Technical University of Denmark, 4000 Roskilde (Denmark); Danish Workpackage for the ESS Design Update Phase, 2800 Lyngby (Denmark); Institute for Energy Conversion, Technical University of Denmark, 4000 Roskilde (Denmark); Andersen, Ken H. [European Spallation Source ESS AB, 22100 Lund (Sweden)

2013-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Low power integrated pumping and valving arrays for microfluidic systems  

DOE Patents [OSTI]

Low power integrated pumping and valving arrays which provide a revolutionary approach for performing pumping and valving approach for performing pumping and valving operations in microfabricated fluidic systems for applications such as medical diagnostic microchips. Traditional methods rely on external, large pressure sources that defeat the advantages of miniaturization. Previously demonstrated microfabrication devices are power and voltage intensive, only function at sufficient pressure to be broadly applicable. This approach integrates a lower power, high-pressure source with a polymer, ceramic, or metal plug enclosed within a microchannel, analogous to a microsyringe. When the pressure source is activated, the polymer plug slides within the microchannel, pumping the fluid on the opposite side of the plug without allowing fluid to leak around the plug. The plugs also can serve as microvalves.

Krulevitch, Peter A. (Pleasanton, CA); Benett, William J. (Livermore, CA); Rose, Klint A. (Livermore, CA); Hamilton, Julie (Tracy, CA); Maghribi, Mariam (Davis, CA)

2006-04-11T23:59:59.000Z

322

Drive piston assembly for a valve actuator assembly  

DOE Patents [OSTI]

A drive piston assembly is provided that is operable to selectively open a poppet valve. The drive piston assembly includes a cartridge defining a generally stepped bore. A drive piston is movable within the generally stepped bore and a boost sleeve is coaxially disposed with respect to the drive piston. A main fluid chamber is at least partially defined by the generally stepped bore, drive piston, and boost sleeve. First and second feedback chambers are at least partially defined by the drive piston and each are disposed at opposite ends of the drive piston. At least one of the drive piston and the boost sleeve is sufficiently configured to move within the generally stepped bore in response to fluid pressure within the main fluid chamber to selectively open the poppet valve. A valve actuator assembly and engine are also provided incorporating the disclosed drive piston assembly.

Sun, Zongxuan (Troy, MI)

2010-02-23T23:59:59.000Z

323

Design and fabrication of microfluidic valves using poly(N-isopropylacrylamide)  

E-Print Network [OSTI]

A compact printable microfluidic valve composed of poly(N-isopropylacrylamide) has been designed, fabricated, and tested. The design of the valve consists of filling microwells with poly(NIPAAm) and bonding PDMS channels ...

Reticker-Flynn, Nathan Edward

2008-01-01T23:59:59.000Z

324

E-Print Network 3.0 - aortic valve area Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

<< < 1 2 3 4 5 > >> 1 A Computational Model of Aging and Calcification in the Aortic Heart Valve Summary: fluid velocity and aortic valve opening area (AVA) at each age. These...

325

E-Print Network 3.0 - aortic heart valve Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

heart valve Search Powered by Explorit Topic List Advanced Search Sample search results for: aortic heart valve Page: << < 1 2 3 4 5 > >> 1 Non-Invasive Evaluation of Opening and...

326

E-Print Network 3.0 - aortic valve regurgitation Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

regurgitation Page: << < 1 2 3 4 5 > >> 1 Interaction between the mitral and aortic heart valve Summary: or regurgitation. In 2001, of all valve diseases in the left ventricle,...

327

E-Print Network 3.0 - aortic valve thickening Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

<< < 1 2 3 4 5 > >> 1 A Computational Model of Aging and Calcification in the Aortic Heart Valve Summary: of a normal, healthy valve thicken and become less extensible over...

328

Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson*  

E-Print Network [OSTI]

Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson to render the electromechanical valve actuator (EVA) globally asymptotically stable (GAS). Elec model. Here, we demonstrate and prove that our controller renders the system GAS without any assumption

Stefanopoulou, Anna

329

Eaton Throat-Valve Element prototype concept. Phase 1  

SciTech Connect (OSTI)

As part of an ongoing effort to improve techniques for simulating nuclear blasts, the US Army Research Laboratory has been studying the merits of computer-controlled valves. The valve studies have been aimed at providing the Department of Defense with the capacity to conduct nuclear blast and thermal survivability testing on full-scale tactical vehicles. This report documents the development and findings of a computer model that simulates the behavior of the Eaton-Throat Valve Element (ETVE) prototype, and describes a proposed modification concept for the ETVE. The computer model reveals three main findings: (1) the ETVE chatters during the open cycle, (2) the chatter is caused by the high gas forces on the sliding sleeve as the driver gas passes through its portholes, and (3) the chatter is aggravated because there is insufficient damping in the system. The INEL recommends opening the ETVE by sliding the sleeve toward the downstream end of the valve instead of toward the upstream end, as the ETVE is presently configured, and to provide additional damping to the system. However, neither of these configuration changes can be achieved easily, and a redesign and analysis f the ETVE must be completed prior to performing any work on the current ETVE prototype. The ETVE simulation model proved to be an extremely valuable tool in analyzing the qualitative nature of the valve`s operation. Further development of the model is recommended for quantitative analysis and design of the ETVE. This report explains the model and stress analysis findings, and proposes a redesign concept.

Stacey, M.R.; Arendts, J.G.; Berry, R.A.; Korth, G.E.; Schwieder, P.R.; Sekot, J.P.; Snow, S.D.

1993-12-01T23:59:59.000Z

330

Piping retrofit reduces valve-damaging flow vibration  

SciTech Connect (OSTI)

This article describes how excessive flow-induced vibration was escalating safety relief valve maintenance at an alarming pace until simple piping modifications eliminated the problem. Public Service Co. of Colorado's (PSCO) Cherokee Station Unit 4 had been experiencing excessive hot and cold reheat safety valve maintenance. From 1990 through 1993, expenditures exceeded $150,000, including a complete refurbishing in 1990. Furthermore, from 1990 to 1992 the incurred costs of contracting VR certificate repairs accumulated to more than $50,000. Such exorbitant maintenance costs were unique among PSCO's generating system.

Webb, M.; Ellenberger, P.

1995-01-01T23:59:59.000Z

331

RECOVERY ACT: DYNAMIC ENERGY CONSUMPTION MANAGEMENT OF ROUTING TELECOM AND DATA CENTERS THROUGH REAL-TIME OPTIMAL CONTROL (RTOC): Final Scientific/Technical Report  

SciTech Connect (OSTI)

This final scientific report documents the Industrial Technology Program (ITP) Stage 2 Concept Development effort on Data Center Energy Reduction and Management Through Real-Time Optimal Control (RTOC). Society is becoming increasingly dependent on information technology systems, driving exponential growth in demand for data center processing and an insatiable appetite for energy. David Raths noted, 'A 50,000-square-foot data center uses approximately 4 megawatts of power, or the equivalent of 57 barrels of oil a day1.' The problem has become so severe that in some cases, users are giving up raw performance for a better balance between performance and energy efficiency. Historically, power systems for data centers were crudely sized to meet maximum demand. Since many servers operate at 60%-90% of maximum power while only utilizing an average of 5% to 15% of their capability, there are huge inefficiencies in the consumption and delivery of power in these data centers. The goal of the 'Recovery Act: Decreasing Data Center Energy Use through Network and Infrastructure Control' is to develop a state of the art approach for autonomously and intelligently reducing and managing data center power through real-time optimal control. Advances in microelectronics and software are enabling the opportunity to realize significant data center power savings through the implementation of autonomous power management control algorithms. The first step to realizing these savings was addressed in this study through the successful creation of a flexible and scalable mathematical model (equation) for data center behavior and the formulation of an acceptable low technical risk market introduction strategy leveraging commercial hardware and software familiar to the data center market. Follow-on Stage 3 Concept Development efforts include predictive modeling and simulation of algorithm performance, prototype demonstrations with representative data center equipment to verify requisite performance and continued commercial partnering agreement formation to ensure uninterrupted development, and deployment of the real-time optimal control algorithm. As a software implementable technique for reducing power consumption, the RTOC has two very desirable traits supporting rapid prototyping and ultimately widespread dissemination. First, very little capital is required for implementation. No major infrastructure modifications are required and there is no need to purchase expensive capital equipment. Second, the RTOC can be rolled out incrementally. Therefore, the effectiveness can be proven without a large scale initial roll out. Through the use of the Impact Projections Model provided by the DOE, monetary savings in excess of $100M in 2020 and billions by 2040 are predicted. In terms of energy savings, the model predicts a primary energy displacement of 260 trillion BTUs (33 trillion kWh), or a 50% reduction in server power consumption. The model also predicts a corresponding reduction of pollutants such as SO2 and NOx in excess of 100,000 metric tonnes assuming the RTOC is fully deployed. While additional development and prototyping is required to validate these predictions, the relative low cost and ease of implementation compared to large capital projects makes it an ideal candidate for further investigation.

Ron Moon

2011-06-30T23:59:59.000Z

332

Optimization Journals, Sites, Societies  

E-Print Network [OSTI]

Optimization Online Links. Optimization related societies. Mathematical Optimization Society SIAM INFORMS. Optimization related journals. Mathematical...

333

Monovalve with integrated fuel injector and port control valve, and engine using same  

DOE Patents [OSTI]

Each cylinder of an internal combustion engine includes a combined gas exchange valve and fuel injector with a port control valve. The port control valve operates to open either an intake passage or an exhaust passage. The operation of the combined device is controlled by a pair of electrical actuators. The device is hydraulically actuated.

Milam, David M. (Metamora, IL)

2002-01-01T23:59:59.000Z

334

Wear and wear mechanism simulation of heavy-duty engine intake valve and seat inserts  

SciTech Connect (OSTI)

A silicon-chromium alloy frequently used for heavy-duty diesel engine intake valves was tested against eight different insert materials with a valve seat wear simulator. Wear resistance of these combinations was ranked. For each test, the valve seat temperature was controlled at approximately 510 C, the number of cycles was 864,000 (or 24 h), and the test load was 17,640 N. The combination of the silicon-chromium valve against a cast iron insert produced in the least valve seat wear, whereas a cobalt-base alloy insert produced the highest valve seat wear. In the overall valve seat recession ranking, however, the combination of the silicon-chromium valve and an iron-base chromium-nickel alloy insert had the least total seat recession, whereas the silicon-chromium valve against cobalt-base alloy, cast iron, and nickel-base alloy inserts had significant seat recession. Hardness and microstructure compatibility of valve and insert materials are believed to be significant factors in reducing valve and insert wear. The test results indicate that the mechanisms of valve seat and insert wear are a complex combination of adhesion and plastic deformation. Adhesion was confirmed by material transfer, while plastic deformation was verified by shear strain (or radial flow) and abrasion. The oxide films formed during testing also played a significant role. The prevented direct metal-to-metal contact and reduced the coefficient of friction on seat surfaces, thereby reducing adhesive and deformation-controlled wear.

Wang, Y.S.; Narasimhan, S.; Larson, J.M.; Schaefer, S.K. [Eaton Corp., Marshall, MI (United States). Engine Components Operations] [Eaton Corp., Marshall, MI (United States). Engine Components Operations

1998-02-01T23:59:59.000Z

335

APPLICATION OF BUTTERFLY VALVES FOR FREE DISCHARGE, MINIMUM PRESSURE DROP, AND FOR CHOKING CAVITATION  

E-Print Network [OSTI]

CAVITATION Butterfly valves are commonly used as control valves in applications where the pressure drops and the use of a butterfly valve for flashing or choking cavitation service. Free discharge typically produces high pipe velocities at moderate pressure drops, and choking cavitation typically produces high

Rahmeyer, William J.

336

Worcester 1 Inch Solenoid Actuated Gas Operated VPS System Ball Valve  

SciTech Connect (OSTI)

1 inch Gas-operated full-pod ball valve incorporates a solenoid and limit switches as integral park of the actuator. The valve is normally open and fails safe to the closed position. The associated valve position switch is class GS.

MISKA, C.R.

2000-11-13T23:59:59.000Z

337

Experimental study on the cause of insufficiency of a transcutaneous pulmonary valve replacement  

E-Print Network [OSTI]

Experimental study on the cause of insufficiency of a transcutaneous pulmonary valve replacement for the replacement of pulmonary heart valves. This technique is a minimally invasive alternative to the replacement on known causes for insufficiencies of transcutaneous heart valve replacements. Out of that information

Berlin,Technische Universität

338

Wireless Sensing, Monitoring and Optimization for Campus-Wide Steam Distribution  

SciTech Connect (OSTI)

The US Congress has passed legislation dictating that all government agencies establish a plan and process for improving energy efficiencies at their sites. In response to this legislation, Oak Ridge National Laboratory (ORNL) has recently conducted a pilot study to explore the deployment of a wireless sensor system for a real-time measurement-based energy efficiency optimization. With particular focus on the 12-mile long steam distribution network in our campus, we propose an integrated system-level approach to optimize energy delivery within the steam distribution system. Our approach leverages an integrated wireless sensor and real-time monitoring capability. We make real time state assessment on the steam trap health and steam flow estimate of the distribution system by mounting acoustic sensors on the steam pipes/traps/valves and observing measurements of these sensors with state estimators for system health. Our assessments are based on a spectral-based energy signature scheme that interprets acoustic vibration sensor data to estimate steam flow rates and assess steam traps status. Experimental results show that the energy signature scheme has the potential to identify different steam trap states and it has sufficient sensitivity to estimate flow rate. Moreover, results indicate a nearly quadratic relationship over the test region between the overall energy signature factor and flow rate in the pipe. We are able to present the steam flow and steam trap status, sensor readings, and the assessed alerts as an interactive overlay within a web-based Google Earth geographic platform that enables decision makers to take remedial action. The goal is to achieve significant energy-saving in steam lines by monitoring and acting on leaking steam pipes/traps/valves. We believe our demonstration serves as an instantiation of a platform that extends implementation to include newer modalities to manage water flow, sewage and energy consumption.

Olama, Mohammed M [ORNL; Allgood, Glenn O [ORNL; Kuruganti, Phani Teja [ORNL; Sukumar, Sreenivas R [ORNL; Woodworth, Ken [ORNL; Lake, Joe E [ORNL

2011-11-01T23:59:59.000Z

339

Load Expansion of Stoichiometric HCCI Using Spark Assist and Hydraulic Valve Actuation  

SciTech Connect (OSTI)

A spark-assist homogeneous charge compression ignition (SA-HCCI) operating strategy is presented here that allows for stoichiometric combustion from 1000-3000 rpm, and at loads as high as 750 kPa net IMEP. A single cylinder gasoline engine equipped with direct fuel injection and fully variable hydraulic valve actuation (HVA) is used for this experimental study. The HVA system enables negative valve overlap (NVO) valve timing for hot internal EGR. Spark-assist stabilizes combustion over a wide range of engine speeds and loads, and allows for stoichiometric operation at all conditions. Characteristics of both spark-ignited combustion and HCCI are present, with combustion analysis showing a distinctive spark ignited phase of combustion, followed by a much more rapid HCCI combustion phase. At high load, the maximum pressure rise rate is controlled by a combination of spark timing and retarding the intake valve closing angle. The latter reduces the effective compression ratio, and therefore the compressive temperatures, allowing the high load limit of the operating range to be expanded. The SA-HCCI operating strategy exhibits improved thermal efficiency at most operating conditions, with fuel consumption improvements up to 9% realized at light engine loads. The SA-HCCI operating strategy presented here does not provide an efficiency advantage at all operating points compared to SI combustion; a decrease was observed at the highest speed and at loads above 500 kPa net IMEP. At light engine loads the majority of the heat release takes place during the HCCI phase of the heat release, and as such the NOx emissions are very low and are similar to levels observed in pure HCCI. At higher loads, a larger portion of the heat release takes place during the spark ignited phase of combustion, which produces NOx emissions that are much higher than is typically associated with HCCI, but still represent a decrease from conventional SI combustion. By limiting the fuel/air mixture to stoichiometric conditions, the higher NOx emissions do not represent an implementation barrier to this strategy because compatibility is maintained with very effective conventional 3-way catalysts.

Szybist, James P [ORNL; Nafziger, Eric J [ORNL

2010-01-01T23:59:59.000Z

340

Pumps, pipes and valves: The heart of a system  

SciTech Connect (OSTI)

This is a guide to suppliers of pumps, pipes and valves for construction or repair of hazardous materials. The article contains a compilation of the suppliers/manufacturers and how to contact them, the corrosion resistance of the component, whether double-secondary containment is available, and the material used to construct the component.

NONE

1996-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Covered Product Category: Pre-Rinse Spray Valves  

Broader source: Energy.gov [DOE]

The Federal Energy Management Program (FEMP) provides acquisition guidance and Federal efficiency requirements across a variety of product categories, including pre-rinse spray valves, which are a FEMP-designated product category. Federal laws and requirements mandate that agencies meet these efficiency requirements in all procurement and acquisition actions that are not specifically exempted by law.

342

Motor current signature analysis for determining operational readiness of motor-operated valves (MOVs)  

SciTech Connect (OSTI)

Motor current signature analysis (MCSA) is a novel diagnostic process for condition monitoring of electric-motor-driven mechanical equipment (e.g., pumps, motor-operated valves, compressors, and processing machinery). The MCSA process identifies, characterizes, and trends over time the instantaneous load variations of mechanical equipment in order to diagnose changes in the condition of the equipment (e.g., due to degradation or service wear), which, if allowed to continue, may lead to failure. It monitors the instantaneous variations (noise content) in the electric current flowing through the power leads to the electric motor that drives the equipment. The motor itself thereby acts as a transducer, sensing both large and small, long-term and rapid, mechanical load variations and converting them to variations in the induced current generated in the motor windings. This motor current noise signature is detected, amplified, and further processed as needed to examine its time domain and frequency domain (spectral) characteristics. The operational principles of MCSA and the nonintrusive data collection apparatus and procedure used with MOVs will be described. Data collected from MOVs in both laboratory and in-plant environments will also be shown to illustrate the ability of MCSA to ''see'' the detailed inner workings of the valve and operator and thus to detect degraded performance at an incipient stage. (Set of 18 vugraphs)

Kryter, R.C.; Haynes, H.D.

1987-01-01T23:59:59.000Z

343

Plastic-lined valves are virtually trouble-free in caustic, acid pipelines  

SciTech Connect (OSTI)

Chevron renovated the naphthenic acid plant, part of the Pascagoula, Mississippi Refinery of Chevron U.S.A. Inc., in mid-1979. They installed plastic-lined valves in the caustic and acid water piping systems. The valves combine the excellent sealing characteristics of a plug valve with the minimal rotary contact surface and low pressure drop of a butterfly valve. The valve has a molded-in-place PTFE liner resistant to abrasives and corrosives at temperatures of 450/sup 0/F, and is rated for pressures from full vacuum to 150 psi.

Not Available

1983-02-01T23:59:59.000Z

344

Aging and service wear of air-operated valves used in safety-related systems at nuclear power plants  

SciTech Connect (OSTI)

Air-operated valves (AOVs) are used in a variety of safety-related applications at nuclear power plants. They are often used where rapid stroke times are required or precise control of the valve obturator is required. They can be designed to operate automatically upon loss of power, which is often desirable when selecting components for response to design basis conditions. The purpose of this report is to examine the reported failures of AOVs and determine whether there are identifiable trends in the failures related to predictable causes. This report examines the specific components that comprise a typical AOV, how those components fail, when they fail, and how such failures are discovered. It also examines whether current testing frequencies and methods are effective in predicting such failures.

Cox, D.F.; McElhaney, K.L.; Staunton, R.H.

1995-05-01T23:59:59.000Z

345

Combustion engine with fuel injection system, and a spray valve for such an engine  

SciTech Connect (OSTI)

This paper describes a fuel system for a combustion engine have a cylinder with an air inlet passage. It comprises: a fuel spray valve having a fuel injection nozzle for spraying fuel into the cylinder air inlet passage and having a fuel spray valve passage leading to the nozzle, means for mounting the fuel spray valve to position the nozzle to open into the cylinder air inlet passage adjacent the cylinder, a fuel pump for providing fuel under pressure to the fuel spray valve passage to be sprayed from the fuel spray valve nozzle, and a fuel heating device connectable to an electrical power supply and disposed adjacent to the valve to be energized for heating the fuel to enhance finer spraying thereof by the fuel spray valve nozzle, the fuel heating device comprising means defining a spiral fuel flow path of selected length connected to and coaxial with the fuel spray valve passage to dispose the selected length of fuel flow path closely adjacent to the fuel spray valve passage, and a fuel heating element comprising a thermistor of a ceramic material of positive temperature coefficient of resistivity arranged to heat the selected length of the spiral fuel flow path to transfer heat to the fuel flowing in the spiral fuel flow path throughout the selected length of the spiral fuel flow path to substantially heat the fuel at a location closely adjacent to the fuel spray valve passage to enhance vaporizing of fuel being sprayed from the valve nozzle.

Wechem, G.V.; Beunk, G.; Van Den Elst, F.; Gerson, P.M.

1991-10-08T23:59:59.000Z

346

Nondestructive evaluation of silicon-nitride ceramic valves from engine duration test.  

SciTech Connect (OSTI)

In this study, we investigated impact and wear damage in silicon-nitride ceramic valves that were subjected to an engine duration test in a natural-gas engine. A high-speed automated laser-scattering system was developed for the nondestructive evaluation (NDE) of 10 SN235P silicon-nitride valves. The NDE system scans the entire valve surface and generates a two-dimensional scattering image that is used to identify location, size and relative severity of subsurface damage in the valves. NED imaging data were obtained at before and at 100 and 500 hours of the engine duration test. The NDE data were analyzed and compared with surface photomicrographs. Wear damage was found in the impact surface of all valves, expecially for exhaust valves. However, the NDE examination did not detect subsurface damage such as cracks or spalls in these engine-tested valves.

Sun, J. G.; Trethewey, J. S.; Vanderspiegle, N. N.; Jensen, J. A.; Nuclear Engineering Division; Caterpillar, Inc.

2008-01-01T23:59:59.000Z

347

Magnetism reflectometer study shows LiF layers improve efficiency in spin valve devices  

SciTech Connect (OSTI)

New, more efficient materials for spin valves - a device used in magnetic sensors, random access memories, and hard disk drives - may be on the way based on research using the magnetism reflectometer at Oak Ridge National Laboratory (ORNL). Spin valve devices work by means of two or more conducting magnetic material layers that alternate their electrical resistance depending on the layers alignment. Giant magnetoresistance is a quantum mechanical effect first observed in thin film structures about 20 years ago. The effect is observed as a significant change in electrical resistance, depending on whether the magnetization of adjacent ferromagnetic layers is in a parallel or an antiparallel magnetic alignment. 'What we are doing here is developing new materials. The search for new materials suitable for injecting and transferring carriers with a preferential spin orientation is most important for the development of spintronics,' said Valeria Lauter, lead instrument scientist on the magnetism reflectometer at the Spallation Neutron Source (SNS), who collaborated on the experiment. The researchers discovered that the conductivity of such materials is improved when an organic polymer semiconductor layer is placed between the magnetic materials. Organic semiconductors are now the material of choice for future spin valve devices because they preserve spin coherence over longer times and distances than conventional semiconductors. While research into spin valves has been ongoing, research into organic semiconductors is recent. Previous research has shown that a 'conductivity mismatch' exists in spin valve systems in which ferromagnetic metal electrodes interface with such organic semiconductors as Alq3 ({pi}-conjugated molecule tris(8-hydroxy-quinoline) aluminium). This mismatch limits the efficient injection of the electrons from the electrodes at the interface with the semiconductor material. However, lithium fluoride (LiF), commonly used in light-emitting diodes, has been found to enhance the injection of electrons through the semiconductor. Researchers from the University of Alabama and ORNL used polarized neutrons at the magnetism reflectometer at SNS to investigate the electronic, magnetic, and structural properties of the electrodes in a novel system. In this system, the magnetic layers cobalt and Ni{sub 80}Fe{sub 20} are interfaced with spacer layers composed of the organic semiconductor Alq3. A coupling layer of LiF is inserted to separate the magnetized layers from the semiconductor. 'ALQ3 is an organic semiconductor material,' said Lauter. 'Normally in these systems a first magnetic layer is grown on a hard substrate so that one can get the controlled magnetic parameters. Then you grow the organic semiconductor layer, followed by another magnetic material layer, such as cobalt.' In addition to determining the effect of the LiF layers on the efficiency of the electron injection, the researchers wanted to determine the magnetic properties of the cobalt and Ni{sub 80}Fe{sub 20} as well as the interfacial properties: whether there is interdiffusion of cobalt through the LiF layer to the semiconductor, for example. The researchers used polarized neutrons at beam line 4A to probe the entire, layer-by-layer assembly of the system. 'Reflectometry with polarized neutrons is a perfect method to study thin magnetic films,' Lauter said. 'These thin films - if you put one on a substrate, you see it just like a mirror. However, this mirror has a very complicated internal multilayer structure. The neutrons look inside this complicated structure and characterize each and every interface. Due to the depth sensitivity of the method, we measure the structural and magnetic properties of each layer with the resolution of 0.5 nm. The neutron scattering results found that inserting LiF as a barrier significantly improves the quality of the interface, increasing the injection of electrons from the magnetic layer through the organic semiconductor in the spin valve and enhancing the overall properties of the system. In related work the magneti

Bardoel, Agatha A [ORNL; Lauter, Valeria [ORNL; Szulczewski, Greg J [ORNL

2012-01-01T23:59:59.000Z

348

Optimization Neuroimaging'',  

E-Print Network [OSTI]

Canonical Ridge Analysis with Ridge Parameter Optimization F. ?. Nielsen, L. K. Hansen and S. C - PLS 1 = k 0 = k optimal k k = optimal k k £ £ 0 #12; Canonical Ridge Analysis with Ridge Parameter Optimization F. ?. Nielsen, L. K. Hansen and S. C. Strother The Human Brain Project, P20 MH57180 ``Spatial

Nielsen, Finn ?rup

349

THE EFFECTS OF MAINTENANCE ACTIONS ON THE PFDavg OF SPRING OPERATED PRESSURE RELIEF VALVES  

SciTech Connect (OSTI)

The safety integrity level (SIL) of equipment used in safety instrumented functions is determined by the average probability of failure on demand (PFDavg) computed at the time of periodic inspection and maintenance, i.e., the time of proof testing. The computation of PFDavg is generally based solely on predictions or estimates of the assumed constant failure rate of the equipment. However, PFDavg is also affected by maintenance actions (or lack thereof) taken by the end user. This paper shows how maintenance actions can affect the PFDavg of spring operated pressure relief valves (SOPRV) and how these maintenance actions may be accounted for in the computation of the PFDavg metric. The method provides a means for quantifying the effects of changes in maintenance practices and shows how these changes impact plant safety.

Harris, S.; Gross, R.

2014-04-01T23:59:59.000Z

350

Removable check valve for use in a nuclear reactor  

DOE Patents [OSTI]

A removable check valve for interconnecting the discharge duct of a pump and an inlet coolant duct of a reactor core in a pool-type nuclear reactor. A manifold assembly is provided having an outer periphery affixed to and in fluid communication with the discharge duct of the pump and has an inner periphery having at least one opening therethrough. A housing containing a check valve is located within the inner periphery of the manifold. The upper end of the housing has an opening in alignment with the opening in the manifold assembly, and seals are provided above and below the openings. The lower end of the housing is adapted for fluid communication with the inlet duct of the reactor core.

Dunn, Charlton (Calabasas, CA); Gutzmann, Edward A. (Simi Valley, CA)

1988-01-01T23:59:59.000Z

351

Spin transport in benzofurane bithiophene based organic spin valves  

SciTech Connect (OSTI)

In this paper we present spin transport in organic spin-valves using benzofurane bithiophene (BF3) as spacer layer between NiFe and Co ferromagnetic electrodes. The use of an AlO{sub x} buffer layer between the top electrode and the organic layer is discussed in terms of improvements of stacking topology, electrical transport and oxygen contamination of the BF3 layer. A study of magnetic hysteresis cycles evidences spin-valve behaviour. Transport properties are indicative of unshorted devices with non-linear I-V characteristics. Finally we report a magnetoresistance of 3% at 40 K and 10 mV in a sample with a 50 nm thick spacer layer, using an AlO{sub x} buffer layer.

Palosse, Mathieu; Sguy, Isabelle; Bedel-Pereira, lena [CNRS, LAAS, 7 avenue du Colonel Roche, F-31400 Toulouse (France) [CNRS, LAAS, 7 avenue du Colonel Roche, F-31400 Toulouse (France); Universit de Toulouse (France); UPS, INSA, INP, ISAE (France); LAAS (France) [France; CEMES, F-31077 Toulouse (France)] [France; Villeneuve-Faure, Christina [Universit de Toulouse (France) [Universit de Toulouse (France); UPS, INSA, INP, ISAE (France); LAAS (France) [France; CEMES, F-31077 Toulouse (France) [France; LAPLACE, Universit Paul Sabatier, 118, route de Narbonne 31062 Toulouse Cedex 9 (France); Mallet, Charlotte; Frre, Pierre [MOLTECH-Anjou, UMR CNRS 6200, Universit dAngers, 2 Bd Lavoisier 49045 ANGERS Cedex (France)] [MOLTECH-Anjou, UMR CNRS 6200, Universit dAngers, 2 Bd Lavoisier 49045 ANGERS Cedex (France); Warot-Fonrose, Bndicte; Biziere, Nicolas [Universit de Toulouse (France) [Universit de Toulouse (France); UPS, INSA, INP, ISAE (France); LAAS (France) [France; CEMES, F-31077 Toulouse (France) [France; CNRS, CEMES-CNRS UPR 8011, 29 rue Jeanne Marvig, BP 94347, FR-31055 Toulouse Cedex 4 (France); Bobo, Jean-Franois, E-mail: jfbobo@cemes.fr [Universit de Toulouse (France) [Universit de Toulouse (France); UPS, INSA, INP, ISAE (France); LAAS (France) [France; CEMES, F-31077 Toulouse (France) [France; CNRS, CEMES-ONERA, NMH, 2 avenue Edouard Belin, FR-31055 Toulouse Cedex 4 (France)

2014-01-15T23:59:59.000Z

352

Gasoline-like Fuel Effects on High-load, Boosted HCCI Combustion Employing Negative Valve Overlap Strategy  

SciTech Connect (OSTI)

In recent years a number of studies have demonstrated that boosted operation combined with external EGR is a path forward for expanding the high load limit of homogeneous charge compression ignition (HCCI) operation with the negative valve overlap (NVO) valve strategy. However, the effects of fuel composition with this strategy have not been fully explored. In this study boosted HCCI combustion is investigated in a single-cylinder research engine equipped with direct injection (DI) fueling, cooled external exhaust gas recirculation (EGR), laboratory pressurized intake air, and a fully-variable hydraulic valve actuation (HVA) valve train. Three fuels with significant compositional differences are investigated: regular grade gasoline (RON = 90.2), 30% ethanol-gasoline blend (E30, RON = 100.3), and 24% iso-butanol-gasoline blend (IB24, RON = 96.6). Results include engine loads from 350 to 800 kPa IMEPg for all fuels at three engine speeds 1600, 2000, and 2500 rpm. All operating conditions achieved thermal efficiency (gross indicated efficiency) between 38 and 47%, low NOX emissions ( 0.1 g/kWh), and high combustion efficiency ( 96.5%). Detailed sweeps of intake manifold pressure (atmospheric to 250 kPaa), EGR (0 25% EGR), and injection timing are conducted to identify fuel-specific effects. The major finding of this study is that while significant fuel compositional differences exist, in boosted HCCI operation only minor changes in operational conditions are required to achieve comparable operation for all fuels. In boosted HCCI operation all fuels were able to achieve matched load-speed operation, whereas in conventional SI operation the fuel-specific knock differences resulted in significant differences in the operable load-speed space. Although all fuels were operable in boosted HCCI, the respective air handling requirements are also discussed, including an analysis of the demanded turbocharger efficiency.

Kalaskar, Vickey B [ORNL] [ORNL; Szybist, James P [ORNL] [ORNL; Splitter, Derek A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

353

Engine control system having speed-based timing  

DOE Patents [OSTI]

A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

Willi, Martin L. (Dunlap, IL); Fiveland, Scott B. (Metamora, IL); Montgomery, David T. (Edelstein, IL); Gong, Weidong (Dunlap, IL)

2012-02-14T23:59:59.000Z

354

Engine control system having fuel-based timing  

DOE Patents [OSTI]

A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a sensor configured to generate a signal indicative of an amount of an air/fuel mixture remaining within the cylinder after completion of a first combustion event and a controller in communication with the actuator and the sensor. The controller may be configured to compare the amount with a desired amount, and to selectively regulate the actuator to adjust a timing of the engine valve associated with a subsequent combustion event based on the comparison.

Willi, Martin L. (Dunlap, IL); Fiveland, Scott B. (Metamora, IL); Montgomery, David T. (Edelstein, IL); Gong, Weidong (Dunlap, IL)

2012-04-03T23:59:59.000Z

355

Optimizing Control- A Survey  

E-Print Network [OSTI]

timation Int. J. of Sy,tems Science, 17,No 8, (1986), 1220 C ; Sec comments to Brdys et al. 10 Cutler C.R. & Perry ILT. Rea.l Time Optimization with Multivll.riable Control is Required to Maximize Profits Computcr.! and Chemical Enginccring, 1, No 5....) the constraints .s (K ,11. ,E.) ~ Q where In geneml, the solution to this problem is an optimal control problem since the inputs.ll would be calculated llll a function of time. Optimizing control methods make~ some simplifying 1.18 sumptions about...

Preisig, H. A.

356

Optimal Quantum Pumps  

E-Print Network [OSTI]

We study adiabatic quantum pumps on time scales that are short relative to the cycle of the pump. In this regime the pump is characterized by the matrix of energy shift which we introduce as the dual to Wigner's time delay. The energy shift determines the charge transport, the dissipation, the noise and the entropy production. We prove a general lower bound on dissipation in a quantum channel and define optimal pumps as those that saturate the bound. We give a geometric characterization of optimal pumps and show that they are noiseless and transport integral charge in a cycle. Finally we discuss an example of an optimal pump related to the Hall effect.

J. E. Avron; A. Elgart; G. M. Graf; L. Sadun

2001-07-12T23:59:59.000Z

357

HCCI engine control and optimization  

E-Print Network [OSTI]

3.2 HCCI Cycle Model . . . . . . . . . . . . . . . 3.2.1v Chapter 7 Optimizing HCCI Engine Combustion TimingWork . . . . . . . . . . . . . . . 1.2.1 HCCI Models for

Killingsworth, Nicholas J.

2007-01-01T23:59:59.000Z

358

HCCI engine control and optimization  

E-Print Network [OSTI]

3.6.3 Comparison with Experimental Engine 3.77 Optimizing HCCI Engine Combustion Timing Controller GainsExperimental Engine . . . . 2.1 Thermal Management . . . . .

Killingsworth, Nicholas J.

2007-01-01T23:59:59.000Z

359

Technology Reinvestment Program/Advanced ``Zero Emission'' Control Valve (Phase II)  

SciTech Connect (OSTI)

The objectives of this effort are to determine, develop and demonstrate the feasibility of significantly reducing the cost and expanding the applications for a family of Advanced Zero Emissions Control Valves that meets the fugitive emissions requirements of the 1990 Amendments to the Clean Air Act. This program is a direct technology spin-off from the valve technology that is critical to the US Navy's Nuclear Powered Fleet. These zero emissions valves will allow the Hydrocarbon and Chemical Processing Industries, etc., to maintain their competitiveness and still meet environmental and safety requirements. Phase 2 is directed at refining the basic technologies developed during Phase 1 so that they can be more readily selected and utilized by the target market. In addition to various necessary certifications, the project will develop a full featured digital controller with ``smart valve'' growth capability, expanding valve sizes/applications and identifying valve materials to permit applications in severe operational environments.

J. Napoleon

1998-12-01T23:59:59.000Z

360

Development of a thyristor valve for next generation 500kV HVDC transmission systems  

SciTech Connect (OSTI)

A high voltage thyristor valve is the basic component of an HVDC transmission system. Development of a 500kV valve for next generation HVDC transmission systems is described. First, the power loss of the valve is analyzed to decide a reasonable wafer size for the light triggered thyristor. From these results, a six inch diameter wafer size is selected. The light triggered thyristor, with ratings of 8kV and 3.5kA, is developed using the six inch wafer. The designing of the valve employing the thyristor and test results with the prototype valve prove that a 500kV valve can be realized by the design method.

Hasegawa, T. [Kansai Electric Power Co., Inc., Osaka (Japan)] [Kansai Electric Power Co., Inc., Osaka (Japan); Yamaji, K. [Shikoku Electric Power Co., Inc., Takamatsu (Japan)] [Shikoku Electric Power Co., Inc., Takamatsu (Japan); Irokawa, H. [Electric Power Development Co., Ltd., Tokyo (Japan)] [Electric Power Development Co., Ltd., Tokyo (Japan); Shirahama, H.; Tanaka, C.; Akabane, K.

1996-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Computations of high-pressure steam flow in the turbine bypass valve  

SciTech Connect (OSTI)

The objective of the present study is to investigate the steam flow behavior through the high-pressure turbine bypass valve. Efforts have mainly been directed at investigating the process of steam flow and property variations aforementioned bypass valve as well as to obtain correlations between the flow rate and the valve opening ratio. Modeling of the high-pressure turbulent steam flow was performed on a three-dimensional non-staggered grid system by employing the finite volume method and by solving the three-dimensional, turbulent, compressible Navier-Stokes, and energy equations. Through this research, numerous data have been acquired and analyzed. These efforts enable one to obtain a correlation data set for the valve opening versus flow rate coefficient of the valve. One of the significant accomplishments is to use the model presented here to further improve a design of a turbine bypass flow valve.

Amano, R.S.; Draxler, G.R.

1999-07-01T23:59:59.000Z

362

E-Print Network 3.0 - ahmed valve implantation Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

delivery applications Summary: power, on demand valve. Previously, an implantable infusion pump system was inves- tigated... improved in order to power a series thermistor and...

363

E-Print Network 3.0 - aortic valve thickness Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

scaffold Summary: Tissue engineered aortic valves based on a knitted scaffold 12;CIP-DATA LIBRARY TECHNISCHE... UNIVERSITEIT EINDHOVEN Lieshout, Marjolein I. van Tissue...

364

E-Print Network 3.0 - aortic valve insertion Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

scaffold Summary: Tissue engineered aortic valves based on a knitted scaffold 12;CIP-DATA LIBRARY TECHNISCHE... UNIVERSITEIT EINDHOVEN Lieshout, Marjolein I. van Tissue...

365

E-Print Network 3.0 - aortic valve sclerosis Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

aortic valve disease... 21 ... Source: Simmons, Craig A. - Department of Mechanical and Industrial Engineering, University of Toronto Collection: Engineering ; Biology and...

366

NUPRO process vent/MCO check valve - prevent backflow from process vent into MCO  

SciTech Connect (OSTI)

NUPRO process vent/MCO check valve - prevent backflow from process vent into MCO CGI-SNF-D-30-3-P4-040.

VAN KATWIJK, C.

1999-07-01T23:59:59.000Z

367

Operational experience using the novel FixCup collecting main valve  

SciTech Connect (OSTI)

On the occasion of the 1995 AIME conference the new PROven (Pressure Regulated Oven) process to control the pressure in coke ovens individually was introduced. This process was made feasible with a new collecting main valve, termed FixCup, with the aid of this valve a variable flow resistance to the raw gas discharge can be realized using a water immersion system. However, just the application of the FixCup system alone--without any pressure regulation--is very advantageous and cost saving. Thyssen has equipped 30 ovens with the new valve. The special constructive features as well as the operational experience using the FixCup valve are treated.

Giertz, J.; Huhn, F. [DMT-Gesellschaft fuer Forschung und Pruefung mbH, Essen (Germany). Inst. for Cokemaking and Fuel Technology; Spitz, J. [Thyssen Stahl AG, Duisburg (Germany)

1996-12-31T23:59:59.000Z

368

E-Print Network 3.0 - aortic valve surgery Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Medicine ; Chemistry 2 A Computational Model of Aging and Calcification in the Aortic Heart Valve Summary: A Computational Model of Aging and Calcification in the Aortic Heart...

369

E-Print Network 3.0 - aortic valve calcium Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

; Biology and Medicine 2 Inhibition of aortic wall calcification in bioprosthetic heart valves by ethanol pretreatment: Biochemical and Summary: Inhibition of aortic wall...

370

E-Print Network 3.0 - active infective valve Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Summary: Non-invasive assessment of leaflet deformation and mechanical properties in heart valve tissue... -invasive assessment of leaflet deformation and mechanical properties...

371

E-Print Network 3.0 - autologous pulmonary valves Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Ecole Polytechnique, Centre de mathmatiques Collection: Mathematics 2 Autologous Heart Valve Tissue Engineering CIP-DATA LIBRARY TECHNISCHE UNIVERSITEIT EINDHOVEN Summary:...

372

E-Print Network 3.0 - aortic valve implantation Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

and Medicine ; Chemistry 3 Inhibition of aortic wall calcification in bioprosthetic heart valves by ethanol pretreatment: Biochemical and Summary: , Comparison of...

373

Means for positively seating a piezoceramic element in a piezoelectric valve during inlet gas injection  

DOE Patents [OSTI]

A piezoelectric valve in a gas delivery system includes a piezoceramic element bonded to a valve seal and disposed over a valve seat, and retained in position by an O-ring and a retainer; an insulating ball normally biased by a preload spring against the piezoceramic element; an inlet gas port positioned such that upon admission of inlet gas into the valve, the piezoceramic element is positively seated. The inlet gas port is located only on the side of the piezoceramic element opposite the seal. 3 figs.

Wright, K.E.

1994-08-23T23:59:59.000Z

374

Valve performance concept move from preventive to condition-oriented maintenance  

SciTech Connect (OSTI)

As a turnkey supplier of nuclear and fossil power plants, Siemens must pay attention in concentrating, maintaining, and developing the expertise in many areas such as system design, components, materials, quality assurance, and qualification testing within centralized organizations. In the company segment VALVES, Siemens/KWU is staffed with experienced professionals who have serviced the power plant industry for about 25 years. The valve engineers deal with all kinds of valve and actuator-related activities like design ratings, development, qualifications, and ongoing improvements. In this regard, the engineers are involved in nearly all actual problems and suggested solutions through continuing dialogues with utilities, authorities, and vendors of valves and actuators.

Zanner, G.; Kradepohl, P.

1996-12-01T23:59:59.000Z

375

Means for positively seating a piezoceramic element in a piezoelectric valve during inlet gas injection  

DOE Patents [OSTI]

A piezoelectric valve in a gas delivery system includes a piezoceramic element bonded to a valve seal and disposed over a valve seat, and retained in position by an O-ring and a retainer; an insulating ball normally biased by a preload spring against the piezoceramic element; an inlet gas port positioned such that upon admission of inlet gas into the valve, the piezoceramic element is positively seated. The inlet gas port is located only on the side of the piezoceramic element opposite the seal.

Wright, Kenneth E. (Yardley, PA)

1994-01-01T23:59:59.000Z

376

E-Print Network 3.0 - activities addressing valve Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

recommendations for addressing cylinders which utilize these valves. The Problem Air Products and Chemicals, Inc... of potential hazards associated with two specific lots of...

377

Design of Optimal Regulators  

E-Print Network [OSTI]

Current research suggests the use of a liner quadratic performance index for optimal control of regulators in various applications. Some examples include correcting the trajectory of rocket and air vehicles, vibration suppression of flexible structures, and airplane stability. In all these cases, the focus is in suppressing/decreasing system deviations rapidly. However, if one compares the Linear Quadratic Regulator (LQR) solution with optimal solutions (minimum time), it is seen that the LQR solution is less than optimal in some cases indeed (3-6) times that obtained using a minimum time solution. Moreover, the LQR solution is sometimes unacceptable in practice due to the fact that values of control extend beyond admissible limits and thus the designer must choose coefficients in the linear quadratic form, which are unknown. The authors suggest methods which allow finding a quasi-optimal LQR solution with bounded control which is closed to the minimum time solution. They also remand the process of the minimum time decision. Keywords: Optimal regulator, minimum time controller, Linear Quadratic Regulator (LQR). -- This paper is declared a work of the U.S. Government and not subject to copyright protection in the USA. The manuscript is accepted as paper AIAA-2003-6638 by 2nd AIAA Unmanned Unlimited Systems, Technologies, and Operations-Aerospace, Land, and See Conference and Workshop - Exhibit, San Diego, California, USA, 15-18 Sep. 2003.

Alexander Bolonkin; Robert Sierakowski

2007-01-19T23:59:59.000Z

378

Optimization 1-1 Convex Optimization & Duality  

E-Print Network [OSTI]

1 Optimization 1-1 Convex Optimization & Duality EEN634, Spring 2007 BASED ON LECTURES GIVEN AT MIT and Princeton Department of ECE, UMiami Optimization 1-2 #12;2 Optimization 1-3 Optimization 1-4 #12;3 Optimization 1-5 Optimization 1-6 #12;4 Optimization 1-7 Optimization 1-8 #12;5 Optimization 1-9 Optimization 1

Fan, Xingzhe

379

Distributed Generation Dispatch Optimization under Various Electricity Tariffs  

E-Print Network [OSTI]

time of use United States Postal Service v Distributed Generation Dispatch Optimization Under Various Electricity Tariffs

Firestone, Ryan; Marnay, Chris

2007-01-01T23:59:59.000Z

380

Use of duplex stainless steel castings in control valves  

SciTech Connect (OSTI)

Duplex stainless steels have enjoyed rapidly increasing popularity in recent years. For numerous reasons the availability of these alloys in the cast form has lagged behind the availability of the wrought form. Commercial demand for control valves in these alloys has driven development of needed information to move into production. A systematic approach was used to develop specifications, suppliers and weld procedures. Corrosion, stress corrosion cracking (SCC), sulfide stress cracking (SSC) and hardness results are also presented for several alloys including; CD3MN (UNS J92205), CD4MCu (UNS J93370) and CD7MCuN (cast UNS S32550).

Gossett, J.L. [Fisher Controls International, Inc., Marshalltown, IA (United States)

1996-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Performance characteristics of a turbo expander substituted for expansion valve on air-conditioner  

SciTech Connect (OSTI)

An experimental study is conducted on a small turbo expander which could be applied to the expansion process in place of expansion valves in refrigerator or air-conditioner to improve the cycle efficiency by recovering energy from the throttling process. The operating gas is HFC134a and the maximum cooling capacity of experiment apparatus is 32.7 kW. Four different turbo expanders are tested to find the performance characteristics of the turbo expander when they operate at a low partial admission rate. The partial admission rate is 1.70% or 2.37, and expanders are operated in the supersonic flow. In the experiment, pressure and temperature are measured at 10 different locations in the experimental apparatus. In addition to these measurements, output power at the turbo expander is measured through a generator installed on a rotor shaft with the rotational speed. Performance data of the turbo expander are obtained at many part load operations by adjusting the output power of the generator. A maximum of 15.8% total-to-static efficiency is obtained when the pressure ratio and the partial admission ratio are 2.37 and 1.70%, respectively. Experimental results show that the optimal velocity ratio decreases when the pressure ratio is decreased, and peak efficiencies, which are obtained at locally maximized efficiency depending on the operating condition, vary linearly against the subcooling temperature or the pressure ratio. (author)

Cho, Soo-Yong [Department of Mechanical and Aerospace Engineering (ReCAPT), Gyeongsang National University, 900 Gajoa-dong, Jinju 660-701 (Korea); Cho, Chong-Hyun [School of Mechanical and Aerospace Engineering, Gyeongsang National University, 900 Gajoa-dong, Jinju 660-701 (Korea); Kim, Chaesil [Department of Mechanical Engineering, Changwon National University, 9 Sarim-dong, Changwon 641-773 (Korea)

2008-09-15T23:59:59.000Z

382

Potential Viability of a Fast-Acting Micro-Solenoid Valve for Pulsed Detonation Fuel Injection  

E-Print Network [OSTI]

current (A) k spring constant (kg/s2 ) Ll flux leakage inductance (H) L(, x) non-linear coil inductance (H-load conditions, indicating the ability of spring- return micro-valves to function reliably at high frequencies) m mass of movable valve core and spring assembly (kg) n integer number of successive (positive

Texas at Arlington, University of

383

Journal of Biomechanics 34 (2001) 12791289 A nonlinear anisotropic model for porcine aortic heart valves  

E-Print Network [OSTI]

Journal of Biomechanics 34 (2001) 1279­1289 A nonlinear anisotropic model for porcine aortic heart finite element model for porcine heart valves. The model is based on the uniaxial experimental data of porcine aortic heart valve leaflet and the properties of nonlinear composite material. A finite element

Luo, Xiaoyu

384

Microfluidic very large scale integration (mVLSI) with integrated micromechanical valves{  

E-Print Network [OSTI]

Microfluidic very large scale integration (mVLSI) with integrated micromechanical valves{ Ismail40258k Microfluidic chips with a high density of control elements are required to improve device and accessible high-density microfluidic chips, we have fabricated a monolithic PDMS valve architecture

Quake, Stephen R.

385

Thermal Shock Effects Modeling on a Globe Valve Body-Bonnet Bolted Flange Joint  

E-Print Network [OSTI]

and are sources of issues to suppliers and users. This is also the case when it comes to valve reliability. In French nuclear industry, EDF used to work closely with valve suppliers to ensure the reliability. Thus of qualification was created in the beginning of the French nuclear Pressurized Water Reactors (PWR) industry

Paris-Sud XI, Université de

386

Wakefield induced Losses in the Manual Valves of the TESLA Cryomodule  

E-Print Network [OSTI]

1 Wakefield induced Losses in the Manual Valves of the TESLA Cryomodule M.Dohlus,H.-P.Wedekind,K.Zapfe DeutschesElektronenSynchrotron Notkestr.85,D-22603Hamburg,Germany Abstract The beam pipe of the TESLA valves with spring type rf-shield which are presently used in the linac of the TESLA Test Facility

387

Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson and Anna G. Stefanopoulou*  

E-Print Network [OSTI]

Rendering the Electromechanical Valve Actuator Globally Asymptotically Stable Katherine S. Peterson on Sontag's feedback to render the electromechanical valve actuator (EVA) globally asymptotically stable on a linearized plant model. Here, we demonstrate and prove that our controller renders the system GAS without any

Sontag, Eduardo

388

The superconducting spin valve and triplet superconductivity I.A. Garifullin a,n  

E-Print Network [OSTI]

The superconducting spin valve and triplet superconductivity I.A. Garifullin a,n , P.V. Leksin s t r a c t A review of our recent results on the spin valve effect is presented. We have used coefficient DF and the exchange splitting I of the conduction band in the F layer [1]. For pure Fe the value

Fominov, Yakov

389

Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation  

E-Print Network [OSTI]

Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions)" #12;Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions, cavitation, fluid flow load, CFD. Abstract: The evaluation of fluid forces on the stem is important for wear

Paris-Sud XI, Université de

390

Proceedings of the 2nd symposium on valves for coal conversion and utilization  

SciTech Connect (OSTI)

The 2nd symposium on valves for coal conversion and utilization was held October 15 to 17, 1980. It was sponsored by the US Department of Energy, Morgantown Energy Technology Center, in cooperation with the Valve Manufacturers Association. Seventeen papers have been entered individually into EDB and ERA. (LTN)

Maxfield, D.A. (ed.)

1981-01-01T23:59:59.000Z

391

Condition monitoring of motor-operated valves in nuclear power plants Pierre Granjon  

E-Print Network [OSTI]

Condition monitoring of motor-operated valves in nuclear power plants Pierre Granjon Gipsa of nuclear power plants. Unfortunately, today's policies present a major drawback. Indeed, these monitoring safety constraints: nuclear power plants. Key components of such systems are motor-operated valves (MOVs

Boyer, Edmond

392

Department of Mechanical and Nuclear Engineering Spring 2012 Electro-Mechanically Actuated Trip and Throttle Valve  

E-Print Network [OSTI]

a special type of fail-safe valve for steam turbines. This valve closes rapidly to stop steam flow into a turbine, during emergency situations, to prevent injury and damage to the turbine. Some steam turbine engineers from both Exlar and Dresser-Rand to complete component and material selection for the final design

Demirel, Melik C.

393

Percutaneous Valve Replacement: Significance of Different Delivery Systems In Vitro and In Vivo  

SciTech Connect (OSTI)

Background and purpose. Percutaneous heart valve replacement is an exciting growing field in cardiovascular medicine yet still with some major problems. Only sophisticated improvement of the instruments could make it a real alternative to conventional surgery. Therefore, the aim of this study was to evaluate different delivery devices for percutaneous heart valve replacement in vitro and in vivo. Methods. A catheter prototype designed by our group, and two commercially available devices for the delivery of esophageal stents and aortic endoprostheses, were tested. After in vitro experiments, an ovine animal model of transfemoral pulmonary valve implantation was established using biological valved self-expanding stents. Only the delivery device for aortic endografts (Medtronic, Talent, Santa Rosa, CA, USA) allowed fast in vitro procedures without material fatigue. This device was chosen for the in vivo tests. Results. Technical success was achieved in 9 of 10 animals (90%). One animal died after perforation of the ventricular wall. Orthotopic pulmonary placement was performed in 6 animals and intentional supravalvular valved stent placement in 3 animals. Conclusions. An adequate in vitro model for this evolving field of interventional heart valve replacement is presented. Furthermore, the present study pinpoints the key characteristics that are mandatory for a delivery system in percutaneous pulmonary valve implantation. With regard to the delivery device's ductility observed during this 'venous' study, an approach to transfemoral aortic valve implantation seems feasible.

Attmann, Tim; Lutter, Georg, E-mail: lutter@kielheart.uni-kiel.de; Quaden, Rene [Christian Albrechts University of Kiel, Department of Cardiovascular Surgery, School of Medicine (Germany); Jahnke, Thomas [Christian Albrechts University of Kiel, Department of Radiology, School of Medicine (Germany); Rumberg, Kristin; Cremer, Jochen [Christian Albrechts University of Kiel, Department of Cardiovascular Surgery, School of Medicine (Germany); Muller-Hulsbeck, Stefan [Christian Albrechts University of Kiel, Department of Radiology, School of Medicine (Germany)

2006-06-15T23:59:59.000Z

394

Valve characterization to implement feed-forward control of hydraulically actuated joints  

E-Print Network [OSTI]

This thesis characterizes the flow behavior of a Hydraforce SP08-47CL valve given a specific pulse-width modulation (pwm) duty cycle. With a description of valve behavior, a feed-forward term can be implemented in the ...

Carey, Abby (Abby M.)

2008-01-01T23:59:59.000Z

395

Optimization Online - Optimal Design of Electrical Machines ...  

E-Print Network [OSTI]

Jun 8, 2011 ... Optimal Design of Electrical Machines: Mathematical Programming ... Science and Engineering (Multidisciplinary Design Optimization ).

Sonia Cafieri

2011-06-08T23:59:59.000Z

396

Direct optimization overly optimizes data Kazunori Yoshizawa  

E-Print Network [OSTI]

OPINION Direct optimization overly optimizes data Kazunori Yoshizawa Systematic Entomology optimization is a criterion that recognizes sequence alignment and tree search as a single epistemological optimization criterion, all data partitions are combined and optimized simultaneously along with the same tree

Yoshizawa, Kazunori

397

Fluid-driven reciprocating apparatus and valving for controlling same  

DOE Patents [OSTI]

A control valve assembly for alternately actuating a pair of fluid-driven free-piston devices by using fluid pressure communication therebetween. Each control valve is switched by a pressure signal depending on the state of its counterpart's piston. The communication logic is arranged to provide overlap of the forward strokes of the pistons, so that at least one of the pair will always be pressurized. Thus, uninterrupted pumping of liquid is made possible from a pair of free-piston pumps. In addition, the speed and frequency of piston stroking is entirely dependent on the mechanical power load applied. In the case of a pair of pumps, this enables liquid delivery at a substantially constant pressure over the full range of flow rates, from zero to maximum flow. One embodiment of the invention utilized two pairs of fluid-driven free-piston devices whereby a bipropellant liquid propulsion system may be operated, so as to provide continuous flow of both fuel and oxidizer liquids when used in rocket applications, for example.

Whitehead, John C. (Davis, CA); Toews, Hans G. (East Aurora, NY)

1993-01-01T23:59:59.000Z

398

Two-phase flow characteristics in multiple orifice valves  

SciTech Connect (OSTI)

This work presents an experimental investigation on the characteristics of two-phase flow through multiple orifice valve (MOV), including frictional pressure drop and void fraction. Experiments were carried out using an MOV with three different sets of discs with throat thickness-diameter ratios (s/d) of 1.41, 1.66 and 2.21. Tests were run with air and water flow rates ranging between 1.0 and 3.0 m{sup 3}/h, respectively. The two-phase flow patterns established for the experiment were bubbly and slug. Two-phase frictional multipliers, frictional pressure drop and void fraction were analyzed. The determined two-phase multipliers were compared against existing correlations for gas-liquid flows. None of the correlations tested proved capable of predicting the experimental results. The large discrepancy between predicted and measured values points at the role played by valve throat geometry and thickness-diameter ratio in the hydrodynamics of two-phase flow through MOVs. A modification to the constants in the two-phase multiplier equation used for pipe flow fitted the experimental data. A comparison between computed frictional pressure drop, calculated with the modified two-phase multiplier equation and measured pressure drop yielded better agreement, with less than 20% error. (author)

Alimonti, Claudio [Sapienza University of Rome, Department ICMA, Via Eudossiana 18, 00184 Roma (Italy); Falcone, Gioia; Bello, Oladele [The Harold Vance Department of Petroleum Engineering, Texas A and M University, 3116 TAMU, Richardson Building, College Station, TX 77843 (United States)

2010-11-15T23:59:59.000Z

399

Optimal design of AC filter circuits in HVDC converter stations  

SciTech Connect (OSTI)

This paper investigates the reactive power as well as the harmonic conditions on both the valve and the AC-network sides of a HVDC converter station. The effect of the AC filter circuits is accurately modeled. The program is then augmented by adding an optimization routine. It can identify the optimal filter configuration, yielding the minimum current distortion factor at the AC network terminals for a prespecified fundamental reactive power to be provided by the filter. Several parameter studies were also conducted to illustrate the effect of accidental or intentional deletion of one of the filter branches.

Saied, M.M.; Khader, S.A. [Kuwait Univ. (Kuwait). Electrical and Computer Engineering Dept.

1995-12-31T23:59:59.000Z

400

Interdiffusion in CoFeCu multilayers and its application to spin-valve structures for data storage  

E-Print Network [OSTI]

, the interdiffusion coefficients for all layers in the spin valve have to be determined. For diffusion drivenInterdiffusion in CoFe?Cu multilayers and its application to spin-valve structures for data storage, Pennsylvania 15213-3890 Received 13 February 2003; accepted 30 April 2003 Spin-valve structures might

Laughlin, David E.

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Percutaneous Transcatheter One-Step Mechanical Aortic Disc Valve Prosthesis Implantation: A Preliminary Feasibility Study in Swine  

SciTech Connect (OSTI)

Purpose. To evaluate the feasibility of one-step implantation of a new type of stent-based mechanical aortic disc valve prosthesis (MADVP) above and across the native aortic valve and its short-term function in swine with both functional and dysfunctional native valves. Methods. The MADVP consisted of a folding disc valve made of silicone elastomer attached to either a nitinol Z-stent (Z model) or a nitinol cross-braided stent (SX model). Implantation of 10 MADVPs (6 Z and 4 SX models) was attempted in 10 swine: 4 (2 Z and 2 SX models) with a functional native valve and 6 (4 Z and 2 SX models) with aortic regurgitation induced either by intentional valve injury or by MADVP placement across the native valve. MADVP function was observed for up to 3 hr after implantation. Results. MADVP implantation was successful in 9 swine. One animal died of induced massive regurgitation prior to implantation. Four MADVPs implanted above functioning native valves exhibited good function. In 5 swine with regurgitation, MADVP implantation corrected the induced native valve dysfunction and the device's continuous good function was observed in 4 animals. One MADVP (SX model) placed across native valve gradually migrated into the left ventricle. Conclusion. The tested MADVP can be implanted above and across the native valve in a one-step procedure and can replace the function of the regurgitating native valve. Further technical development and testing are warranted, preferably with a manufactured MADVP.

Sochman, Jan [Institute for Clinical and Experimental Medicine, Intensive Care Unit, Clinic of Cardiology (Czech Republic)], E-mail: jan.sochman@medicon.cz; Peregrin, Jan H.; Rocek, Miloslav [Institute for Clinical and Experimental Medicine, Department of Diagnostic and Interventional Radiology (Czech Republic); Timmermans, Hans A.; Pavcnik, Dusan; Roesch, Josef [Oregon Health and Sciences University, Dotter Interventional Institute (United States)

2006-02-15T23:59:59.000Z

402

The use of MAVIS II to integrate the modeling and analysis of explosive valve interactions  

SciTech Connect (OSTI)

The MAVIS II computer program provides for the modeling and analysis of explosive valve interactions. This report describes the individual components of the program and how MAVIS II is used with other available tools to integrate the design and understanding of explosive valves. The rationale and model used for each valve interaction is described. Comparisons of the calculated results with available data have demonstrated the feasibility and accuracy of using MAVIS II for analytical studies of explosive valve interactions. The model used for the explosive or pyrotechnic used as the driving force in explosive valves is the most critical to be understood and modeled. MAVIS II is an advanced version that incorporates a plastic, as well as elastic, modeling of the deformations experienced when plungers are forced into a bore. The inclusion of a plastic model has greatly expanded the use of MAVIS for all categories (opening, closure, or combined) of valves, especially for the closure valves in which the sealing operation requires the plastic deformation of either a plunger or bore over a relatively large area. In order to increase its effectiveness, the use of MAVIS II should be integrated with the results from available experimental hardware. Test hardware such as the Velocity Interferometer System for Any Reflector (VISAR) and Velocity Generator test provide experimental data for accurate comparison of the actual valve functions. Variable Explosive Chamber (VEC) and Constant Explosive Volume (CEV) tests are used to provide the proper explosive equation-of-state for the MAVIS calculations of the explosive driving forces. The rationale and logistics of this integration is demonstrated through an example. A recent valve design is used to demonstrate how MAVIS II can be integrated with experimental tools to provide an understanding of the interactions in this valve.

Ng, R.; Kwon, D.M.

1998-12-31T23:59:59.000Z

403

E85 Optimized Engine through Boosting, Spray-Optimized DIG, VCR and Variable Valvetrain  

SciTech Connect (OSTI)

The use of biofuels for internal combustion engines has several well published advantages. The biofuels, made from biological sources such as corn or sugar cane, are renewable resources that reduce the dependence on fossil fuels. Fuels from agricultural sources can therefore reduce a countries energy dependency on other nations. Biofuels also have been shown to reduce CO2 emissions into the atmosphere compared to traditional fossil based fuels. Because of these benefits several countries have set targets for the use of biofuels, especially ethanol, in their transportation fuels. Small percentages of ethanol are common place in gasoline but are typically limited to 5 to 8% by volume. Greater benefits are possible from higher concentrations and some countries such as the US and Sweden have encouraged the production of vehicles capable of operating on E85 (85% denatured ethanol and 15% gasoline). E85 capable vehicles are normally equipped to run the higher levels of ethanol by employing modified fuel delivery systems that can withstand the highly corrosive nature of the alcohol. These vehicles are not however equipped to take full advantage of ethanol's properties during the combustion process. Ethanol has a much higher blend research octane number than gasoline. This allows the use of higher engine compression ratios and spark advance which result in more efficient engine operation. Ethanol's latent heat of vaporization is also much higher that gasoline. This higher heat of vaporization cools the engine intake charge which also allows the engine compression ratio to be increased even further. An engine that is optimized for operation on high concentrations of ethanol therefore will have compression ratios that are too high to avoid spark knock (pre-ignition) if run on gasoline or a gasoline/ethanol blend that has a low percentage alcohol. An engine was developed during this project to leverage the improved evaporative cooling and high octane of E85 to improve fuel economy and offset E85's lower energy content. A 2.0 L production Direct Injection gasoline, (DIg) engine employing Dual Independent Cam Phasing, (DICP) and turbo charging was used as the base engine. Modified pistons were used to increase the geometric compression ratio from 9.2:1 to 11.85:1 by modifying the pistons and adding advanced valvetrain to proved control of displacement and effective compression ratio through valve timing control. The advanced valvetrain utilized Delphi's two step valvetrain hardware and intake cam phaser with increased phasing authority of 80 crank angle degrees. Using this hardware the engine was capable of operating knock free on all fuels tested from E0-E85 by controlling effective compression ratio using a Late Intake Valve Closing, (LIVC) strategy. The LIVC strategy results in changes in the trapped displacement such that knock limited torque for gasoline is significantly lower than E85. The use of spark retard to control knock enables higher peak torque for knock limited fuels, however a loss in efficiency results. For gasoline and E10 fuels, full effective displacement could not be reached before spark retard produced a net loss in torque. The use of an Early Intake Valve Closing, (EIVC) strategy resulted in an improvement of engine efficiency at low to mid loads for all fuels tested from E0- E85. Further the use of valve deactivation, to a single intake valve, improved combustion stability and enabled throttle-less operation down to less than 2 bar BMEP. Slight throttling to trap internal residual provided additional reductions in fuel consumption. To fully leverage the benefits of E85, or ethanol blends above E10, would require a vehicle level approach that would take advantage of the improved low end torque that is possible with E85. Operating the engine at reduced speeds and using advanced transmissions (6 speeds or higher) would provide a responsive efficient driving experience to the customer. The vehicle shift and torque converter lockup points for high ethanol blends could take advantage of the significant efficiency ad

Keith Confer; Harry Husted

2011-05-31T23:59:59.000Z

404

Thermodynamic Optimization of Finite Time Processes By R.S. Berry, V.A. Kazakov, S. Sieniutycz, Z. Szwast, and A.M. Tsirlin  

E-Print Network [OSTI]

driven by solar energy. These areas have all been significantly impacted by the ideas and methods-time thermodynamics problems including the much-needed disclaimers of exactly what the subject can and cannot do examples of finite-time thermodynamics problems that illustrate the theory as it is developed

Salamon, Peter

405

Distributed Optimization System  

DOE Patents [OSTI]

A search system and method for controlling multiple agents to optimize an objective using distributed sensing and cooperative control. The search agent can be one or more physical agents, such as a robot, and can be software agents for searching cyberspace. The objective can be: chemical sources, temperature sources, radiation sources, light sources, evaders, trespassers, explosive sources, time dependent sources, time independent sources, function surfaces, maximization points, minimization points, and optimal control of a system such as a communication system, an economy, a crane, and a multi-processor computer.

Hurtado, John E. (Albuquerque, NM); Dohrmann, Clark R. (Albuquerque, NM); Robinett, III, Rush D. (Tijeras, NM)

2004-11-30T23:59:59.000Z

406

Typed Self-Optimization  

E-Print Network [OSTI]

Optimizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 and 26. APPENDIX B Optimizations Included in thisappendix are the three optimization steps which together

Brown, Matt

2013-01-01T23:59:59.000Z

407

Coal slurry letdown valve-concept test phase. Final report  

SciTech Connect (OSTI)

The results of the concept test phase of a novel pressure letdown device indicate usefulness of the concept. The device, using staged letdown, was designed to minimize erosion damage by minimizing slurry velocities through the pressure restrictions. Tests were performed on air, steam/water and a coal slurry with a flashing component. Two valve sizes were used. Based on the results of these tests, the following conclusions were drawn: (1) the basic operating principle of designing for a constant velocity through the orifice restrictions is correct; (2) multiphase pressure letdown can be modeled; (3) temperature profiles are predictable; and (4) erosion in three-phase flow is a complex phenomenon. Recommendations for further work on the device include: (1) development of a controllable device; (2) correlation of further test data; and (3) study of flow regimes where erosion is minimized. 9 refs., 48 figs., 6 tabs.

Collins, E.R. Jr.; Suitor, J.W.

1984-01-01T23:59:59.000Z

408

Electromagnetic valve for controlling the flow of molten, magnetic material  

DOE Patents [OSTI]

An electromagnetic valve for controlling the flow of molten, magnetic material is provided, which comprises an induction coil for generating a magnetic field in response to an applied alternating electrical current, a housing, and a refractory composite nozzle. The nozzle is comprised of an inner sleeve composed of an erosion resistant refractory material (e.g., a zirconia ceramic) through which molten, magnetic metal flows, a refractory outer shell, and an intermediate compressible refractory material, e.g., unset, high alumina, thermosetting mortar. The compressible refractory material is sandwiched between the inner sleeve and outer shell, and absorbs differential expansion stresses that develop within the nozzle due to extreme thermal gradients. The sandwiched layer of compressible refractory material prevents destructive cracks from developing in the refractory outer shell. 5 figs.

Richter, T.

1998-06-16T23:59:59.000Z

409

Configuration and temperature dependence of magnetic damping in spin valves  

SciTech Connect (OSTI)

Using vector-analyzer ferromagnetic resonance, we have studied the microwave susceptibility of a Py/Co/Cu/Co/MnIr spin valve over a large temperature range (5-450 K) and as a function of the magnetic configuration. An effective magnetization and Gilbert damping constant of 1.1 T and 0.021, respectively, are found for the permalloy free layer, with no discernible variation in temperature observed for either quantities. In contrast, the pinned layer magnetization is reduced by heating, and the exchange bias collapses near a temperature of 450 K. The ferromagnetic resonance linewidth of the free layer increases by 500 MHz when the layer magnetizations are aligned in antiparallel, which is attributed to a configuration-dependent contribution to the damping from spin pumping effects.

Joyeux, X.; Devolder, T.; Kim, Joo-Von; Gomez de la Torre, Y.; Eimer, S.; Chappert, C. [Institut d'Electronique Fondamentale, University Paris-Sud, 91405 Orsay (France); UMR8622, CNRS, University Paris-Sud, 91405 Orsay (France)

2011-09-15T23:59:59.000Z

410

Strength and fatigue of NT551 silicon nitride and NT551 diesel exhaust valves  

SciTech Connect (OSTI)

The content of this report is excerpted from Mark Andrew's Ph.D. Thesis (Andrews, 1999), which was funded by a DOE/OTT High Temperature Materials Laboratory Graduate Fellowship. It involves the characterization of NT551 and valves fabricated with it. The motivations behind using silicon nitride (Si{sub 3}N{sub 4}) as an exhaust valve for a diesel engine are presented in this section. There are several economic factors that have encouraged the design and implementation of ceramic components for internal combustion (IC) engines. The reasons for selecting the diesel engine valve for this are also presented.

Andrews, M.J.; Werezczak, A.A.; Kirkland, T.P.; Breder, K.

2000-02-01T23:59:59.000Z

411

Jet-controlled freeze valve for use in a glass melter  

DOE Patents [OSTI]

A drain valve for use in furnace for the melting of thermoplastic material is disclosed. The furnace includes a drain cavity formed in its bottom for withdrawing a flow of thermoplastic material. The drain valve includes a flow member which include a flow tube having an inlet and outlet for the material, and coaxially disposed concentric tubular members defining annuli surrounding the flow tube. The tubular members include heating and cooling means for the flow tube. The drain valve can also be used in a furnace of glass melting that includes a drain cavity for withdrawing molten glass from the furnace.

Routt, K.R.

1985-07-29T23:59:59.000Z

412

Proceedings of the symposium on inservice testing of pumps and valves  

SciTech Connect (OSTI)

The 1990 Symposium on Inservice Testing of Pumps and Valves, jointly sponsored by the Board on Nuclear Codes and Standards of the American Society of Mechanical Engineers and by the Nuclear Regulatory Commission, provided a forum for the discussion of current programs and methods for inservice testing at nuclear power plants. The symposium also provided an opportunity to discuss the need to improve inservice testing in order to ensure the reliable performance of pumps and valves. The participation of industry representatives, regulators, and consultants resulted in the discussion of a broad spectrum of ideas and perspectives regarding the improvement of inservice testing of pumps and valves at nuclear power plants.

Not Available

1990-10-01T23:59:59.000Z

413

Toward optimized code generation through model-based optimization  

E-Print Network [OSTI]

Toward optimized code generation through model- based optimization Asma Charfi, Chokri Mraidha.gerard, francois.terrier}@cea.fr Pierre Boulet LIFL, CNRS/INRIA, Université de Lille 1, Parc de la Haute Borne, Bât tools like synthesis of system's application by automatic code generation. Real-Time and Embedded

Paris-Sud XI, Université de

414

Control and optimization system and method for chemical looping processes  

DOE Patents [OSTI]

A control system for optimizing a chemical loop system includes one or more sensors for measuring one or more parameters in a chemical loop. The sensors are disposed on or in a conduit positioned in the chemical loop. The sensors generate one or more data signals representative of an amount of solids in the conduit. The control system includes a data acquisition system in communication with the sensors and a controller in communication with the data acquisition system. The data acquisition system receives the data signals and the controller generates the control signals. The controller is in communication with one or more valves positioned in the chemical loop. The valves are configured to regulate a flow of the solids through the chemical loop.

Lou, Xinsheng; Joshi, Abhinaya; Lei, Hao

2014-06-24T23:59:59.000Z

415

An analysis of the relationship of heart sound time intervals to respiratory sinus arrhythmia  

E-Print Network [OSTI]

to be close to the clinically significant left ventricular ejection time (LVET). These results were obtained in a laboratory setting. Recording heart sounds at the trachea was not easy. The heart sound signal was not very stable. In order for a useful... VALVE R - LEFT VENTRICLE Figure 1. Crossectional view of the heart showing the four chambers and the four valves. l20 X IOO E E 80 oI 60 In 40 Aornc volve opens PROTODIASTOLE EJECTION~ COIJTRACTION~ I, r Aortic valve closes r ISOMETRIC...

Schorsch, Eric Todd

1987-01-01T23:59:59.000Z

416

Multiperiod Refinery Planning Optimization  

E-Print Network [OSTI]

Multiperiod Refinery Planning Optimization with Nonlinear CDU Models Abdulrahman Alattas, Advisor #12;Refinery Planning Model Development 2 Extension to Multiperiod Planning #12;3 Multiperiod Refinery: refinery configuration Determine · What crude oil to process and in which time period? · The quantities

Grossmann, Ignacio E.

417

Abstract--An algorithm is presented which provides an op-timal solution to the problem of scheduling non-relocatable time  

E-Print Network [OSTI]

of the interval, historical and current demand for the time frame, and a variety of other variables such as price to respond appropri- ately to price as a mechanism of control whereas the offline greedy and the online FCFS to this limited resource among multiple price-competing customers. Market-based mechanisms have been successfully

418

Optimization Online - Nonlinear Optimization Submissions - 2003  

E-Print Network [OSTI]

Optimization Online is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

419

Optimization Online - Nonlinear Optimization Submissions - 2001  

E-Print Network [OSTI]

Optimization Online is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

420

Optimization Online - Global Optimization Submissions - 2007  

E-Print Network [OSTI]

Optimization Online is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Optimization Online - Global Optimization Submissions - 2001  

E-Print Network [OSTI]

Optimization Online is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

422

Optimization Online - Nonlinear Optimization Submissions - 2000  

E-Print Network [OSTI]

Optimization Online is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

423

Optimization Online - Combinatorial Optimization Submissions - 2002  

E-Print Network [OSTI]

Optimization Online is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

424

HIGH-FREQUENCY MAGNETOCAPACITANCE EFFECT IN ORGANIC SPIN VALVE WITH A  

E-Print Network [OSTI]

HIGH-FREQUENCY MAGNETOCAPACITANCE EFFECT IN ORGANIC SPIN VALVE WITH A 3,4,9,10-PERYLENE Institute of Atomic and Molecular Sciences Academia Sinica, 10617 Taipei, Taiwan *mtlin@phys.ntu

Lin, Minn-Tsong

425

Classification of heart valve single leg separations from acoustic clinical measurements  

SciTech Connect (OSTI)

Our system classifies the condition (intact or single leg separated) of in vivo Bjork-Shiley Convexo-Concave (BSCC) heart valves by processing acoustic measurements of clinical heart valve opening sounds. We use spectral features as inputs to a two-stage classifier, which first classifies individual heart beats, then classifies valves. Performance is measured by probability of detection and probability of false alarm, and by confidence intervals on the probability of correct classification. The novelty of the work lies in the application of advanced techniques to real heart valve data, and extensions of published algorithms that enhance their applicability. We show that even when given a very small number of training samples, the classifier can achieve a probability of correct classification of 100%.

Clark, G.A.; Bowman, B.C.; Boruta, N.; Thomas, G.H.; Jones, H.E.; Buhl, M.R.

1994-05-01T23:59:59.000Z

426

E-Print Network 3.0 - ahmed glaucoma valve Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Saati MD, Ronalee Lo PhD, Po-Ying Li PhD, Ellis Meng PhD, Rohit Varma MD MPH, AND Mark S. Humayun MD Summary: and morphology after Ahmed glaucoma valve implantation during...

427

Rankine cycle condenser pressure control using an energy conversion device bypass valve  

DOE Patents [OSTI]

The disclosure provides a waste heat recovery system and method in which pressure in a Rankine cycle (RC) system of the WHR system is regulated by diverting working fluid from entering an inlet of an energy conversion device of the RC system. In the system, an inlet of a controllable bypass valve is fluidly coupled to a working fluid path upstream of an energy conversion device of the RC system, and an outlet of the bypass valve is fluidly coupled to the working fluid path upstream of the condenser of the RC system such that working fluid passing through the bypass valve bypasses the energy conversion device and increases the pressure in a condenser. A controller determines the temperature and pressure of the working fluid and controls the bypass valve to regulate pressure in the condenser.

Ernst, Timothy C; Nelson, Christopher R; Zigan, James A

2014-04-01T23:59:59.000Z

428

Percutaneous aortic valve replacement in a re-animated postmortem heart  

E-Print Network [OSTI]

transcatheter implantation of heart valve prosthesis for thein apex of post-mortem heart (lower view). B C A Figure 5A.descending aorta in lambs. Eur Heart J. 2002;23:1045-49. 5.

White, Jennifer; Sun, Amy; Killien, Lauren; Evangelista, Dennis

2006-01-01T23:59:59.000Z

429

VALVE FUNNEL SPRING PIN PRESS PERFORMANCE AND FUNCTIONAL REQUIREMENTS EVALUATION FOR SPECIAL TOOLS AND EQUIPMENT  

SciTech Connect (OSTI)

This evaluation allows use of the valve funnel spring pin press and describes appropriate handling instructions for the tool. The engineering evaluation is required for operations and field use of special tools and equipment.

WITHERSPOON JT

2009-12-30T23:59:59.000Z

430

Volume 4 Issue 2 www.nasa.gov/centers/stennis February 2009 Stennis tests shuttle valves  

E-Print Network [OSTI]

hydrogen tubing. The call went out to three centers to begin testing aspects of the valve. Engineers the Stennis team faced during the original construction, or during the crossover to successfully execute

431

E-Print Network 3.0 - aortic valve substitution Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

<< < 1 2 3 4 5 > >> 1 A Computational Model of Aging and Calcification in the Aortic Heart Valve Summary: A Computational Model of Aging and Calcification in the Aortic Heart...

432

E-Print Network 3.0 - aortic valve calcification Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

<< < 1 2 3 4 5 > >> 1 A Computational Model of Aging and Calcification in the Aortic Heart Valve Summary: A Computational Model of Aging and Calcification in the Aortic Heart...

433

E-Print Network 3.0 - aortic valve replacement Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

<< < 1 2 3 4 5 > >> 1 A Computational Model of Aging and Calcification in the Aortic Heart Valve Summary: A Computational Model of Aging and Calcification in the Aortic Heart...

434

E-Print Network 3.0 - aortic valve endocarditis Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

are aortic valve disease, present in 12 to 30 percent of cases, and congenital heart disease... in detection of IE.24 TEE is especially important for patients with aortic...

435

Classification of heart valve sounds from experiments in an anechoic water tank  

SciTech Connect (OSTI)

In vivo studies in both sheep and humans were plagued by a number of problems including movement artifacts, biological noise, low signal-to-noise ratio (SNR), chest-wall reverberation, and limited bandwidth recordings as discussed by [1]. To overcome these problems it was decided to record heart valve sounds under controlled conditions deep in an anechoic water tank, free from reverberation noise. The main goal of this experiment was to obtain measurements of ''pure'' heart valve sounds free of the scattering effects of the body. Experiments were conducted at the Transdec facility in San Diego [2]. We used a high quality hydrophone together with a wide-band data acquisition system [2]. We recorded sounds from 100 repetitions of the opening-closing cycles on each of 50 different heart valves, including 21 SLS valves and 29 intact valves. The power spectrum of the opening and closing phases of each cycle were calculated and outlier spectra removed as described by Candy [2]. In this report, we discuss the results of our classification of the heart valve sound measurements. The goal of this classification task was to apply the fundamental classification algorithms developed for the clinical data in 1994 and 1996 to the measurements from the anechoic water tank. From the beginning of this project, LLNL's responsibility has been to process and classify the heart valve sounds. For this experiment, however, we processed both the opening sounds and closing sounds for comparison purposes. The results of this experiment show that the classifier did not perform well because of low signal-to-noise ratio and excessive variability in signal power from beat-to-beat for a given valve.

Axelrod, M C; Clark, G A; Scott, D

1999-06-01T23:59:59.000Z

436

Automated high-throughput flow-through real-time diagnostic system  

DOE Patents [OSTI]

An automated real-time flow-through system capable of processing multiple samples in an asynchronous, simultaneous, and parallel fashion for nucleic acid extraction and purification, followed by assay assembly, genetic amplification, multiplex detection, analysis, and decontamination. The system is able to hold and access an unlimited number of fluorescent reagents that may be used to screen samples for the presence of specific sequences. The apparatus works by associating extracted and purified sample with a series of reagent plugs that have been formed in a flow channel and delivered to a flow-through real-time amplification detector that has a multiplicity of optical windows, to which the sample-reagent plugs are placed in an operative position. The diagnostic apparatus includes sample multi-position valves, a master sample multi-position valve, a master reagent multi-position valve, reagent multi-position valves, and an optical amplification/detection system.

Regan, John Frederick

2012-10-30T23:59:59.000Z

437

Regenerators As Hubs - Optimization Online  

E-Print Network [OSTI]

With its vast data transfer capacities, an optical network is the only mature solution ...... In this respect, the number of times a node appears in the alternative optimal solutions ... nodes in the center become advantageous. ..... fuel vehicles (

2013-09-26T23:59:59.000Z

438

Optimization problems in network connectivity  

E-Print Network [OSTI]

Besides being one of the principal driving forces behind research in algorithmic theory for more than five decades, network optimization has assumed increased significance in recent times with the advent and widespread use ...

Panigrahi, Debmalya

2012-01-01T23:59:59.000Z

439

E85 Optimized Engine through Boosting, Spray Optimized GDi, VCR...  

Broader source: Energy.gov (indexed) [DOE]

Cam Phasing (DICP) and 2-Step Valve Train * Achieve high power density using turbo charging. * Enable low emissions with stratified cold start for fast converter...

440

Risk assessment of drain valve failure in the K-West basin south loadout pit  

SciTech Connect (OSTI)

The drain valve located in the bottom of the K-West Basin South Loadout Pit (SLOP) could provide an additional leak path from the K Basins if the drain valve were damaged during construction, installation, or operation of the cask loading system. For the K-West Basin SLOP the immersion pail support structure (IPSS) has already been installed, but the immersion pail has not been installed in the IPSS. The objective of this analysis is to evaluate the risk of damaging the drain valve during the remaining installation activities or operation of the cask loading system. Valve damage, as used in this analysis, does not necessarily imply large amounts of the water will be released quickly from the basin, rather valve damage implies that the valve's integrity has been compromised. The analysis process is a risk-based uncertainty analysis where best engineering judgement is used to represent each variable in the analysis. The uncertainty associated with each variable is represented by a probability distribution. The uncertainty is propagated through the analysis by Monte Carlo convolution techniques. The corresponding results are developed as a probability distribution and the risk is expressed in terms of the corresponding complementary cumulative distribution function (''risk curve''). The total risk is the area under the ''risk curve''. The risk of potentially dropping a cask into or on the IPSS and damaging the drain valve is approximately 1 x 10{sup -4} to 2 x 10{sup -5} per year. The risk of objects falling behind the IPSS and damaging the valve is 3 x 10{sup -2} to 6 x 10{sup -3} per year. Both risks are expressed as drain value failure frequencies. The risk of objects falling behind the IPSS and damaging the valve can be significantly reduced by an impact limiter and/or installing a gating or plate over the area bounded by the back of the IPSS and the wall of the SLOP. With either of these actions there is a 90 percent confidence that the frequency of drain valve failure would be less than 1 x 10{sup -6} per year.

MORGAN, R.G.

1999-06-23T23:59:59.000Z

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Time Oset Optimization in Digital Broadcasting - Optimization Online  

E-Print Network [OSTI]

French and German premiers as one of the main challenges of European ...... R., Frequency Assignment and Network Planning for Digital Terrestrial Broad-.

442

Matlab-based Optimization: Optimization Toolbox  

E-Print Network [OSTI]

Matlab-based Optimization: the Optimization Toolbox Gene Cliff (AOE/ICAM - ecliff@vt.edu ) 3:00pm Engineering ICAM: Interdisciplinary Center for Applied Mathematics 1 / 37 #12;Matlab's Optimization Toolbox;Matlab's Optimization Toolbox Classifying Optimization Problems A Soup Can Example Intermezzo

Crawford, T. Daniel

443

Fuzzy Optimality and Evolutionary Multiobjective Optimization  

E-Print Network [OSTI]

Fuzzy Optimality and Evolutionary Multiobjective Optimization M. Farina and P. Amato. Pareto optimality is someway ineffective for optimization problems with several (more than three) objectives. In fact the Pareto optimal set tends to become a wide portion of the whole design domain search

Coello, Carlos A. Coello

444

Interconnection networks synthesis and optimization  

E-Print Network [OSTI]

Synthesis and Optimization . . . . . . . . . . .1.Wire Style Optimization . . . . . . . . . . . . . B. PowerSynthesis and Optimization . 1. Overview . . . . . . . . . .

Zhu, Yi

2008-01-01T23:59:59.000Z

445

Processing of prosthetic heart valve sounds for single leg separation classification  

SciTech Connect (OSTI)

Efforts are concentrated on the sounds corresponding to the heart valve opening cycle. Valve opening and closing acoustics present additional information about the outlet strut condition---the structural component implicated in valve failure. The importance of the opening sound for single leg separation detection/classification is based on the fact that as the valve opens, the disk passively hits the outlet strut. The opening sounds thus yield direct information about outlet strut condition with minimal amount of disturbance caused by the energy radiated from the disk. Hence the opening sound is a very desirable acoustic signal to extract. Unfortunately, the opening sounds have much lower signal levels relative to the closing sounds and therefore noise plays a more significant role than during the closing event. Because of this it is necessary to screen the sounds for outliers in order to insure a high sensitivity of classification. Because of the sharp resonances appearing in the corresponding spectrum, a parametric processing approach is developed based on an autoregressive model which was selected to characterize the sounds emitted by the Bjork--Shiley convexo--concave (BSCC) valve during opening cycle. First the basic signals and the extraction process used to create an ensemble of heart valve sounds are briefly discussed. Next, a {ital beat} {ital monitor} capable of rejecting beats that fail to meet an acceptance criteria based on their spectral content is developed. Various approaches that have been utilized to enhance the screened data and produce a reliable {ital heart} {ital valve} {ital spectrogram} which displays the individual sounds (power) as a function of beat number and temporal frequency are discussed. Once estimated, the spectrogram and associated parameters are used to develop features supplied to the various classification schemes. Finally, future work aimed at even further signal enhancement and improved classifier performance is discussed.

Candy, J.V.; Jones, H.E. [University of California, Lawrence Livermore National Laboratory, P.O. Box 808, L-495, Livermore, California 94550 (United States)

1995-06-01T23:59:59.000Z

446

Classification of heart valve sounds from experiments in an anechoic water tank  

SciTech Connect (OSTI)

In vivo studies in both sheep and humans were plagued by a number of problems including movement artifacts, biological noise, low signal-to-noise ratio (SNR), chest-wall reverberation, and limited bandwidth recordings as discussed by [1]. To overcome these problems it was decided to record heart valve sounds under controlled conditions deep in an anechoic water tank, free from reverberation noise, including surface reflections. Experiments were conducted in a deep water tank at the Transdec facility in San Diego, which satisfies these requirements. The Transdec measurements are free of reverberations, but not totally free of acoustic and electrical noise. We used a high quality hydrophone together with a wide-band data acquisition system [2]. We recorded sounds from 100 repetitions of the opening-closing cycles on each of 50 different heart valves, including 21 SLS valves and 29 intact valves. The power spectrum of the opening and closing phases of each cycle were calculated and outlier spectra removed as described by Candy [2]. In this report, we discuss the results of our classification of the heart valve sound measurements. The goal of this classification task was to apply the fundamental classification algorithms developed for the clinical data in 1994 and 1996 to the measurements from the anechoic water tank. From the beginning of this project, LLNL's responsibility has been to process and classify the heart valve opening sounds. For this experiment, however, we processed both the opening sounds and closing sounds for comparison purposes. The results of this experiment show that the classifier did not perform well. We believe this is because of low signal-to-noise ratio and excessive variability in signal power from beat-to-beat for a given valve.

Axelrod, M C; Clark, G A; Scott, D

1999-06-01T23:59:59.000Z

447

Control of Charge Dilution in Turbocharged Diesel Engines via Exhaust Valve Timing  

E-Print Network [OSTI]

Compression Ignition (HCCI) engines high level of EGR can be used to indirectly control combustion initiation and HCCI engines [7, 10]. Conventional external EGR (eEGR), relies on a pressure drop from exhaust manifold

Stefanopoulou, Anna

448

Multi objective optimisation of an electromagnetic valve actuator Nicolas BELLEGARDE, Jean-Claude VANNIER, Philippe DESSANTE, Pierre VIDAL  

E-Print Network [OSTI]

Multi objective optimisation of an electromagnetic valve actuator Nicolas BELLEGARDE, Jean, weight, volume. 1. Notations a Thickness of the mobile part (mm) Slot's coefficient of occupation b

Paris-Sud XI, Université de

449

NET - Optimization Online  

E-Print Network [OSTI]

Optimization Online An E-Print Site for the Optimization Community. Network Optimization submissions; 2001 2003 2004 2005 2006 2007 2008 2009

450

FTN4 OPTIMIZATION TECHNIQUES.  

E-Print Network [OSTI]

3 1st Edition FTN4 OPTIMIZATION TECHNIQUES November 1979O. INTRODUCTION 1. COt1PILER OPTIMIZATIONS 2. SOURCE CODEcode. Most of these optimizations decrease central processor

Authors, Various

2012-01-01T23:59:59.000Z

451

Minimizing the background radiation in the new neutron time-of-flight facility at CERN FLUKA Monte Carlo simulations for the optimization of the n_TOF second experimental line  

E-Print Network [OSTI]

At the particle physics laboratory CERN in Geneva, Switzerland, the Neutron Time-of-Flight facility has recently started the construction of a second experimental line. The new neutron beam line will unavoidably induce radiation in both the experimental area and in nearby accessible areas. Computer simulations for the minimization of the background were carried out using the FLUKA Monte Carlo simulation package. The background radiation in the new experimental area needs to be kept to a minimum during measurements. This was studied with focus on the contributions from backscattering in the beam dump. The beam dump was originally designed for shielding the outside area using a block of iron covered in concrete. However, the backscattering was never studied in detail. In this thesis, the fluences (i.e. the flux integrated over time) of neutrons and photons were studied in the experimental area while the beam dump design was modified. An optimized design was obtained by stopping the fast neutrons in a high Z mat...

Bergstrm, Ida; Elfgren, Erik

2013-06-11T23:59:59.000Z

452

Uncertainty Analysis for a Virtual Flow Meter Using an Air-Handling Unit Chilled Water Valve  

SciTech Connect (OSTI)

A virtual water flow meter is developed that uses the chilled water control valve on an air-handling unit as a measurement device. The flow rate of water through the valve is calculated using the differential pressure across the valve and its associated coil, the valve command, and an empirically determined valve characteristic curve. Thus, the probability of error in the measurements is significantly greater than for conventionally manufactured flow meters. In this paper, mathematical models are developed and used to conduct uncertainty analysis for the virtual flow meter, and the results from the virtual meter are compared to measurements made with an ultrasonic flow meter. Theoretical uncertainty analysis shows that the total uncertainty in flow rates from the virtual flow meter is 1.46% with 95% confidence; comparison of virtual flow meter results with measurements from an ultrasonic flow meter yielded anuncertainty of 1.46% with 99% confidence. The comparable results from the theoretical uncertainty analysis and empirical comparison with the ultrasonic flow meter corroborate each other, and tend to validate the approach to computationally estimating uncertainty for virtual sensors introduced in this study.

Song, Li; Wang, Gang; Brambley, Michael R.

2013-04-28T23:59:59.000Z

453

Renovation and remaining life management techniques for the reliable operation of steam turbine valve casings  

SciTech Connect (OSTI)

Much attention has been focused on the renovation and remaining life management of steam turbine casings. Properly engineered casing repairs, design upgrades, and strategies such as thermal stress monitoring/control, have been successfully employed to keep older steam turbine casings operating reliably until projected plant decommissioning dates. These proven solutions have resulted in a much lower cost alternative to turbine casing replacement. Valve casings are also subject to the rigors of high pressure/temperature operating environments and have a significant replacement cost as well. The same techniques employed to renovate turbine casings can also be successfully applied to valve casings to ensure their reliable operation for the projected plant life. Of particular interest are design upgrades which can be introduced during the renovation. Advances in computer modeling and techniques such as Finite Element analysis have provided engineers with tools not available during the original casing design. This provides an opportunity to not only restore the casings to their original design, but to re-engineer the casings to exceed original design parameters. This paper will cover the engineering analysis of valve casing defects, restoration techniques, and design upgrades. Thermal stress monitoring will be introduced as a technique to manage remaining life. Typical failure modes in various valve casing designs as well as design improvements will be stressed. It will also use case studies to demonstrate the economic and technical advantages of valve and turbine casing renovation.

Rasmussen, D.M.; Otterlee, T.J. [Turbine Consultants, Inc., Milwaukee, WI (United States)

1994-12-31T23:59:59.000Z

454

Apparatus and method for non-invasive diagnosis and control of motor operated valve condition  

DOE Patents [OSTI]

An apparatus compares the torque from an MOV motor with the valve displacement, and from the comparison assesses MOV operating condition. A transducer measures the vibration of the housing of an MOV. The vibrations are due to the motions of the rotating elements within the housing, which motions are directly related to the motion of the valve relative to its seat. Signal processing apparatus analyzes the vibrations to recover the rotations of the rotating elements and thus the motion of the valve plug. Lost motion can also be determined (if a lost motion connection exists) by demodulating the vibration signal and thus taking into account also the lost motion. Simultaneously, the forces applied to the valve are estimated by estimating the torque between the stator and the rotor of the motor. Such torque can be estimated from measuring the input current and voltage alone, using a forgetting factor and a correction for the forgetting factor. A signature derived from relating the torque to the valve position can be used to assess the condition of the MOV, by comparing the signature to signatures for MOVs of known conditions. The vibration analysis components generate signals that relate to the position of elements in the operator. Similarly, the torque estimator estimates the torque output by any type of electric motor, whether or not part of an MOV analysis unit.

Lyon, Richard H. (Belmont, MA); Chai, Jangbom (Seoul, KR); Lang, Jeffrey H. (Sudbury, MA); Hagman, Wayne H. (Belmont, MA); Umans, Stephen D. (Belmont, MA); Saarela, Olli J. (Helsinki, FI)

1997-01-01T23:59:59.000Z

455

Heart valve cardiomyocytes of mouse embryos express the serotonin transporter SERT  

SciTech Connect (OSTI)

Multiple evidence demonstrate a role for serotonin and its transporter SERT in heart valve development and disease. By utilizing a Cre/loxP system driven by SERT gene expression, we recently demonstrated a regionally restricted distribution of SERT-expressing cells in developing mouse heart. In order to characterize the cell types exhibiting SERT expression within the mouse heart valves at early developmental stages, in this study we performed immunohistochemistry for Islet1 (Isl1) and connexin-43 (Cx-43) on heart sections from SERT{sup Cre/+};ROSA26R embryos previously stained with X-gal. We observed the co-localization of LacZ staining with Isl1 labelling in the outflow tract, the right ventricle and the conal region of E11.5 mouse heart. Cx-43 labelled cells co-localized with LacZ stained cells in the forming atrioventricular valves. These results demonstrate the cardiomyocyte phenotype of SERT-expressing cells in heart valves of the developing mouse heart, thus suggesting an active role of SERT in early heart valve development.

Pavone, Luigi Michele [Department of Biological Structures, Functions and Technologies, University of Naples Federico II, Via F. Delpino 1, 80137 Naples (Italy); Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples (Italy)], E-mail: pavone@dbbm.unina.it; Spina, Anna; Lo Muto, Roberta; Santoro, Dionea [Department of Biological Structures, Functions and Technologies, University of Naples Federico II, Via F. Delpino 1, 80137 Naples (Italy); Department of Biochemistry and Medical Biotechnologies, University of Naples Federico II, Naples (Italy); Mastellone, Vincenzo [Department of Experimental Medicine 'G. Salvatore', University of Magna Graecia, Catanzaro (Italy); Avallone, Luigi [Department of Biological Structures, Functions and Technologies, University of Naples Federico II, Via F. Delpino 1, 80137 Naples (Italy)

2008-12-12T23:59:59.000Z

456

Steady-State Flow-Force Compensation in a Hydraulic Spool Valve  

E-Print Network [OSTI]

A high-speed jet flowing inside of a partially-open hydraulic valve is accompanied by a reaction force, also referred to as flow force. The nature of this force has remained a mystery despite an extensive research effort spanning many decades. The momentum theory on the flow force by Lee and Blackburn (1952) explains the origin of the flow force and offers a design solution to shape the valve spool as a turbine bucket. It provides a model to calculate the compensated flow force as well. This paper shows that the model applies to a different flow case due to incorrect assumptions made. A corrected equation is presented based on a detailed analysis of the static-pressure distribution in the valve cavity as well as on a literature review of pressure loss in diffusers and nozzles. The new equation is based on the compensation taking place upstream of the valve orifice, not downstream as assumed by the momentum theory. The new model can be applied to chamfers or notches on the valve spool without the need to machi...

Lugowski, Jan

2013-01-01T23:59:59.000Z

457

Optimization Online - Nonlinear Optimization Submissions - 2014  

E-Print Network [OSTI]

January 2014. Constrained Nonlinear Optimization New active set identification for general constrained optimization and minimax problems. Jin-bao Jian, Yi Liu.

458

Optimization Online - Global Optimization Submissions - 2014  

E-Print Network [OSTI]

Zhao Sun. February 2014. Global optimization on the torus, the sphere and the rotation ... RBFOpt: an open-source library for black-box optimization with costly...

459

Optimization Jason Courter  

E-Print Network [OSTI]

Optimization Jason Courter Foundations of Ecology #12;What is optimization? Maximization Minimization Optimization Natural Selection 1. Variation 2. Heritable Variation 3. Differential Reproduction #12;On Optimal use of a Patchy Environment · Robert MacArthur · Eric Pianka http

Jodice, Patrick

460

Advanced Review Geometry optimization  

E-Print Network [OSTI]

Advanced Review Geometry optimization H. Bernhard Schlegel Geometry optimization is an important part of most quantum chemical calcu- lations. This article surveys methods for optimizing equilibrium geometries, lo- cating transition structures, and following reaction paths. The emphasis is on optimizations

Schlegel, H. Bernhard

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

[SIAM conference on optimization  

SciTech Connect (OSTI)

Abstracts are presented of 63 papers on the following topics: large-scale optimization, interior-point methods, algorithms for optimization, problems in control, network optimization methods, and parallel algorithms for optimization problems.

Not Available

1992-05-10T23:59:59.000Z

462

2006 - Optimization Online  

E-Print Network [OSTI]

Optimization Online is supported by the Mathematical Programming Society and by the Optimization Technology Center. Mathematical Programming Society.

463

Optimization Online - Category Archive  

E-Print Network [OSTI]

Optimization Online. Browse Submissions By Area. Linear, Cone and Semidefinite ... Optimization Online is supported by the Mathematical Optmization Society.

464

Optimization Online - Category Archive  

E-Print Network [OSTI]

Optimization Online. Browse Submissions By Area. Combinatorial Optimization. 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011

465

Optimization Online - Category Archive  

E-Print Network [OSTI]

Optimization Online. Browse Submissions By Area. Integer Programming ... Optimization Online is supported by the Mathematical Optmization Society.

466

Optimization Online - Digest Archive  

E-Print Network [OSTI]

Optimization Online Digest Archive. Subscribe to the digest. ... Online is supported by the Mathematical Optmization Society. Mathematical Optimization Society.

467

Optimization Online - Category Archive  

E-Print Network [OSTI]

Optimization Online. Browse Submissions By Area. Complementarity and ... Optimization Online is supported by the Mathematical Optmization Society.

468

Optimization Online - Category Archive  

E-Print Network [OSTI]

Optimization Online. Browse Submissions By Area. Nonlinear Optimization. 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011...

469

Optimization Online - Coordinators  

E-Print Network [OSTI]

Optimization Online submissions are electronically handled by a team of ... OR and Management Sciences / Integer Programming / Robust Optimization...

470

In this research project I will design and build a demo model of Professor Sun's patented camless valve actuator device. Modern internal combustion engines rely on valves in each  

E-Print Network [OSTI]

valve actuator device. Modern internal combustion engines rely on valves in each cylinder to open, they can be programmed to allow much more efficiency in the combustion cycle at any engine speed, with any the engine and instead replaces it with electronic actuators that can be precisely controlled by the onboard

Minnesota, University of

471

Real-Time Utility System Optimization  

E-Print Network [OSTI]

At the 2002 IETC, we described the benefits of a site-wide utility system simulation model that can translate all in-plant process modifications to the resulting changes in fuel, water and electricity at the factory fence to ensure that process BTUs...

Fernandez-Polanco, D.; Eastwood, A.; Knight, N.

2004-01-01T23:59:59.000Z

472

Characterization of a Micro-Mixing, Pumping, and Valving System Ajay A. Deshmukh, Dorian Liepmann, and Albert P. Pisano  

E-Print Network [OSTI]

Characterization of a Micro-Mixing, Pumping, and Valving System Ajay A. Deshmukh, Dorian Liepmann the performance of a complete pulsatile-flow, continuous micromixing system which utilizes new technology pumps measurements. Keywords: Mixer, Pump, Valve INTRODUCTION A new MEMS pumping and mixing system has been developed

Liepmann, Dorian

473

Spin-dependent thermal and electrical transport in a spin-valve system Zheng-Chuan Wang,1  

E-Print Network [OSTI]

Spin-dependent thermal and electrical transport in a spin-valve system Zheng-Chuan Wang,1 Gang Su,1 governed by thermal processes at high temperature. The so-called spin-valve phenomenon is clearly uncovered, the quantum size effect on the thermal conduc- tance and the Peltier coefficient,2 the diffusive thermopower

Gao, Song

474

Risk assessment of K basin twelve-inch drain valve failure from a postulated seismic initiating event  

SciTech Connect (OSTI)

The Spent Nuclear Fuel (SNF) Project will transfer metallic SNF from the Hanford 105 K-East and 105 K-West Basins to safe interim storage in the Canister Storage Building in the 200 Area. The initial basis for design, fabrication, installation, and operation of the fuel removal systems was that the basin leak rates which could result from a postulated accident condition would not be excessive relative to reasonable recovery operations. However, an additional potential K Basin water leak path is through the K Basin drain valves. Three twelve-inch drain valves are located in the main basin bays along the north wall. The sumps containing the valves are filled with concrete which covers the drain valve body. Visual observations suggest that only the valve's bonnet and stem are exposed above the basin concrete floor. It was recognized, however, that damage of the drain valve bonnet or stem during a seismic initiating event could provide a potential K Basin water leak path. The objectives of this activity are to: (1) evaluate the risk of damaging the three twelve-inch drain valves located along the north wall of the main basin from a seismic initiating event, and (2) determine the associated potential leak rate from a damaged valve.

MORGAN, R.G.

1999-04-06T23:59:59.000Z

475

CFD Analysis of a Novel High Speed Rotary On/Off Valve 283 Proc. of 6th  

E-Print Network [OSTI]

section, and outlet turbine. A CFD model is created for each section, and then verified. The equations that predict the valve performance has been validated for the inlet rail with nozzles and the outlet turbine, valve design, throttle-less control 1 INTRODUCTION Hydraulic actuation systems have been widely used due

Li, Perry Y.

476

Derivative Free Optimization Methods for Optimizing Stirrer ...  

E-Print Network [OSTI]

It also gives a comparison of the two optimization algorithms. Key words: Energy, Numerical Optimization, Derivative-Free Optimization,. Computational Fluid ... numerical simulations are needed for the computation of the fluid flow inside the stirrer for ..... Optimization Methods and Software, 20 (2005) 493-508. [6] A. R. Conn...

2007-02-01T23:59:59.000Z

477

LLNL heart valve condition classification project anechoic testing results at the TRANSDEC evaluation facility  

SciTech Connect (OSTI)

This report first briefly outlines the procedures and support/activation fixture developed at LLNL to perform the heart valve tests in an anechoic-like tank at the US Navy Transducer Evaluation Facility (TransDec) located in San Diego, CA. Next they discuss the basic experiments performed and the corresponding experimental plan employed to gather meaningful data systematically. The signal processing required to extract the desired information is briefly developed along with some of the data. Finally, they show the results of the individual runs for each valve, point out any of the meaningful features and summaries.

Candy, J V

1999-10-31T23:59:59.000Z

478

Spin-transfer switching of orthogonal spin-valve devices at cryogenic temperatures  

SciTech Connect (OSTI)

We present the quasi-static and dynamic switching characteristics of orthogonal spin-transfer devices incorporating an out-of-plane magnetized polarizing layer and an in-plane magnetized spin valve device at cryogenic temperatures. Switching at 12?K between parallel and anti-parallel spin-valve states is investigated for slowly varied current as well as for current pulses with durations as short as 200 ps. We demonstrate 100% switching probability with current pulses 0.6?ns in duration. We also present a switching probability diagram that summarizes device switching operation under a variety of pulse durations, amplitudes, and polarities.

Ye, L., E-mail: ly17@nyu.edu; Gopman, D. B.; Rehm, L.; Backes, D.; Wolf, G.; Kent, A. D. [Department of Physics, New York University, New York, New York 10003 (United States); Ohki, T. [Raytheon BBN Technologies, Cambridge, Massachusetts 02138 (United States); Kirichenko, A. F.; Vernik, I. V.; Mukhanov, O. A. [HYPRES, 175 Clearbrook Road, Elmsford, New York 10523 (United States)

2014-05-07T23:59:59.000Z

479

Fail Save Shut Off Valve for Filtering Systems Employing Candle Filters  

DOE Patents [OSTI]

The invention relates to an apparatus that acts as a fail save shut off valve. More specifically, the invention relates to a fail save shut off valve that allows fluid flow during normal operational conditions, but prevents the flow of fluids in the event of system failure upstream that causes over-pressurization. The present invention is particularly well suited for use in conjunction with hot gas filtering systems, which utilize ceramic candle filters. Used in such a hot gas system the present invention stops the flow of hot gas and prevents any particulate laden gas from entering the clean side of the system.

VanOsdol, John

2006-01-03T23:59:59.000Z

480

In-situ magnetoresistance measurements during patterning of spin valve devices  

E-Print Network [OSTI]

. This dissertation does not exceed the limit of length. Some of the work in this thesis has been published as listed below. Publications Control of the switching properties of magnetic thin films and spin valve devices by patterning, D.Morecroft, C... .W. Leung, N.A. Stelmashenko, J.L. Prieto, D.B. Jardine and M.G. Blamire. IEEE Trans. Mag. 37 Issue: 4 Part: 1 (2001) pp. 2079 2081. In-situ magnetoresistance measurements during patterning of thin films and spin valve devices, D.Morecroft, C...

Morecroft, Deborah

Note: This page contains sample records for the topic "valve timing optimizes" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Fail save shut off valve for filtering systems employing candle filters  

DOE Patents [OSTI]

The invention relates to an apparatus that acts as a fail save shut off valve. More specifically, the invention relates to a fail save shut off valve that allows fluid flow during normal operational conditions, but prevents the flow of fluids in the event of system failure upstream that causes over-pressurization. The present invention is particularly well suited for use in conjunction with hot gas filtering systems, which utilize ceramic candle filters. Used in such a hot gas system the present invention stops the flow of hot gas and prevents any particulate laden gas from entering the clean side of the system.

VanOsdol, John (Fairmont, WV)

2006-01-03T23:59:59.000Z

482

Sealing off a carbon nanotube with a self-assembled aqueous valve for the storage of hydrogen in GPa pressure  

E-Print Network [OSTI]

The end section of a carbon nanotube, cut by acid treatment, contains hydrophillic oxygen groups. Water molecules can self-assemble around these groups to seal off a carbon nanotube and form an "aqueous valve". Molecular dynamics simulations on single-wall (12,12) and (15,15) tubes with dangling carboxyl groups show that the formation of aqueous valves can be achieved both in the absence of and in the presence of high pressure hydrogen. Furthermore, significant diffusion barriers through aqueous valves are identified. It indicates that such valves could hold hydrogen inside the tube with GPa pressure. Releasing hydrogen is easily achieved by melting the "aqueous valve". Such a design provides a recyclable and non- destructive way to store hydrogen in GPa pressure. Under the storage conditions dictated by sealing off the container in liquid water, the hydrogen density inside the container is higher than that for solid hydrogen, which promises excellent weight storage efficiency.

Chen, H Y; Gong, X G; Liu, Zhi-Feng

2012-01-01T23:59:59.000Z

483

Event-driven multithreaded dynamic optimization  

E-Print Network [OSTI]

Speci?c Optimizations . . . . . . . . . . . . . F.3. Trace Optimization Overhead . . . . . . . . . . . . . . .Dynamic Optimization . . . . . . .B. Optimizations with the

Zhang, Weifeng

2006-01-01T23:59:59.000Z

484

Construction integrity assessment report (ETN-98-0005) S-Farm overground transfer (OGT) system valve pit 241-S-B to valve pit 241-S-D  

SciTech Connect (OSTI)

The S-Farm overground transfer (OGT) line will bypass the existing line(s), between valve pits 241-S-B and 241-S-D that no longer meet system requirements. The new OGT line will provide a waste transfer pipeline between these valve pits in support of saltwell pumping activities. The length of the OGT line is approximately 180 ft from pit to pit. The primary pipe is nominal 1-in. diameter stainless steel (SST) braided Ethylene-propylene Diene Monomer (EPDM) hose. The encasement pipe is a nominal 3-in., flanged, SST pipe made up of several different length pipe spool pieces (drawing H-2-829564, sh. 1 and sh. 2). The OGT line slopes from valve pit 241-S-B toward valve pit 241-S-D. At each end, the primary and encasement pipe connect to a pit entry spool piece. The pit entry spool pieces are constructed of prefabricated SST materials. These spool pieces allow for the separation of the primary and encasement pipelines after the pipes have entered the valve pits (drawing H-2-818280, sh. 2). The pit entry spool pieces also allow for leak detection of the encasement pipe at each end (drawing H-2-829564, sh. 2). The OGT encasement pipeline is supported above ground by adjustable height unistrut brackets and precast concrete bases (drawing H-2-829654, sh. 1). The pipeline is heat-traced and insulated. The heat tracing and insulation supply and retain latent heat that prevents waste solidification during transfers and provides freeze protection. The total length of the pipeline is above ground, thereby negating the need for cathodic corrosion protection. This Construction Integrity Assessment Report (CIAR) is prepared by Fluor Daniel Northwest for Numatec Hanford Corporation/Lockheed Martin Hanford Corporation, the operations contractor, and the U. S. Department of Energy, the system owner. The CIAR is intended to verify that construction was performed in accordance with the provisions of Washington Administrative Code, WAC-173-303-640 (3) (c), (e), (f) and (h).

HICKS, D.F.

1999-08-12T23:59:59.000Z

485

Extremum Seeking Control for Soft Landing of an Electromechanical Valve Actuator  

E-Print Network [OSTI]

SPACE Controller Laser Vibrometer Eddy current Sensor Sensor Target Spring Upper Coil Lower Coil Armature Valve by inducing current in a coil of wire to give rise to a magnetic force. This force is then used to affect sets of springs and elec- tromagnets. The pre-load of each spring is set such that they are both always

Stefanopoulou, Anna

486

Evidence for spin selectivity of triplet pairs in superconducting spin valves  

E-Print Network [OSTI]

in spintronics to control the flow of electrons by ferromagnets in a ferromagnet (F1)/normal metal (N)/ferromagnet (F2) spin valve, where F1 acts as the polarizer and F2 the analyser. The feasibility of superconducting spintronics depends on the spin sensitivity...

Banerjee, N.; Smiet, C. B.; Smits, R. G. J.; Ozaeta, A.; Bergeret, F. S.; Blamire, M. G.; Robinson, J. W. A.

2014-01-09T23:59:59.000Z

487

Strength and Fatigue of NT551 Silicon Nitride and NT551 Diesel Exhaust Valves  

SciTech Connect (OSTI)

The content of this report is excerpted from Mark Andrew's Ph.D. Thesis (Andrews, 1999), which was funded by a DOEYOTT High Temperature Materials Laboratory Graduate Fellowship. It involves the characterization of NT551 and valves fabricated with it. Greater detail of the described issues may be found in that reference or through communications with Andrew Wereszczak.

Andrews, M.J.; Wereszczak, A.A.; Kirkland, T.P.; Breder, K.

2000-02-01T23:59:59.000Z

488

Cost effective combined axial fan and throttling valve control of ventilation rate  

E-Print Network [OSTI]

, the throttling valve is employed to restrict airflow at the outlet, so generating a higher static pressure differ levels of moisture, heat and internal gases are generated. For this reason, the lack of effective-based controller and a previously developed scheduled PIP design, yielding a re- duction in power consumption

Sengun, Mehmet Haluk

489

Inhibition of aortic wall calcification in bioprosthetic heart valves by ethanol pretreatment: Biochemical and  

E-Print Network [OSTI]

Inhibition of aortic wall calcification in bioprosthetic heart valves by ethanol pretreatment 16 September 1997; 20 February 1998 Abstract: The effectiveness of ethanol pretreatment on pre was previously demonstrated, and the mechanism of action of ethanol was attributed in part to both lipid removal

Zand, Robert

490

Establishment of the mathematical model for diagnosing the engine valve faults by genetic  

E-Print Network [OSTI]

in a six- cylinders/four-stroke cycle diesel engine, i.e. normal condition, valve-tappet clearance and gas for diagnosing the faults occurring in rotor-bearing system, but current computer programs cannot easily distinguish the orbit shapes automatically. Likewise, when diagnosing the faults in a rolling-element bearing

Fernandez, Thomas

491

Thermocapillary valve for droplet production and sorting Charles N. Baroud,1,  

E-Print Network [OSTI]

for use as microfluidic reactors, if active control of their formation and transport can be achieved. We as a microfluidic valve for two-phase flows. A theoretical model is developed to explain the forces acting on a drop in complex droplet microfluidic systems. PACS numbers: 47.61.-k, 47.55.dm Microfluidic droplets have been

Boyer, Edmond

492

An Active Motion Compensation Instrument for Beating Heart Mitral Valve Surgery  

E-Print Network [OSTI]

An Active Motion Compensation Instrument for Beating Heart Mitral Valve Surgery Daniel T. Kettler) is described. The resulting instrument was tested in user trials under a series of positional error bandwidth, creating a wrist that can operate in the restricted workspace within the heart, and ensuring

493

Industrial Optimization Compact Course  

E-Print Network [OSTI]

Industrial Optimization Compact Course and Challenge Workshop Optimization plays a crucial role of the processes are typically nonlinear and dyna- mic. Thus, complex dynamic optimization or optimal control in industrial optimization. February 17­20, 2014 ·9.00­17.00 IWR ·Im Neuenheimer Feld 368 ·69120 Heidelberg www

Kirches, Christian

494

Analysis of system performance losses due to the reversing valve for a heat pump using R-410a  

SciTech Connect (OSTI)

A traditional reversing valve enables a heat pump to operate in the heating mode or cooling mode by switching the refrigerant flow path through the indoor and outdoor coils, thereby changing the functions of the two heat exchangers. However, the presence of a reversing valve causes additional pressure drops and undesired heat exchange. The objective of this research was to measure the overall effects of a reversing valve on a 3-ton heat pump system using R-401a and make comparisons to the same valve's performance with R-22 as the refrigerant. The experiments included tests of under- and over-sized valves at the same test conditions. Also, the effects of pressure drops and of heat transfer combined with mass leakage on system and compressor performance were analyzed. It was found that the use of a larger (oversized) reversing valve to reduce pressure drops provided only limited performance gains. Also, changing refrigerant from R-22 to R-410a resulted in an increase in mass leakage but did not significantly change the effect that the reversing valve had on the system COP.

Fang, W.; Nutter, D.W.

1999-07-01T23:59:59.000Z

495

Shrinking Procedures and Optimal Algorithms  

E-Print Network [OSTI]

Jun 18, 2012 ... Optimal Stochastic Approximation Algorithms for Strongly Convex Stochastic Composite Optimization, II: Shrinking Procedures and Optimal...

Saeed Ghadimi

2012-06-18T23:59:59.000Z

496

Optimization Online - Multistage Adaptive Robust Optimization for ...  

E-Print Network [OSTI]

Sep 5, 2014 ... ... with the increasing penetration of wind and solar power generation has ... Keywords: Electric energy systems, multistage robust optimization, ... Multistage Adaptive Robust Optimization for the Unit Commitment Problem.

Alvaro Lorca

2014-09-05T23:59:59.000Z

497

Essays on optimal taxation  

E-Print Network [OSTI]

This thesis studies the optimal income tax scheme in four different settings. Chapter 1 focuses on the implications of lack of commitment for the optimal labor and capital income tax rates. It finds that it is optimal to ...

Reis, Catarina (Catarina Luis Monteiro dos)

2007-01-01T23:59:59.000Z

498

Compiler Optimization Jordan Bradshaw  

E-Print Network [OSTI]

Compiler Optimization Jordan Bradshaw #12;Outline Overview Goals and Considerations ­ Scope. 346- 352. Print. "Compiler Optimization." Wikipedia. Wikimedia Foundation, 25 04 2010. Web. 25 Apr 2010. #12;Compiler Optimization Goals: ­ Speed

Valtorta, Marco

499

Pessimistic Bilevel Optimization  

E-Print Network [OSTI]

We study a variant of the pessimistic bilevel optimization problem, which comprises constraints that must be satisfied for any optimal solution of a subordinate (lower-level) optimization problem. We present conditions ...

Wiesemann, Wolfram

500

Optimization and geophysical inverse problems  

E-Print Network [OSTI]

for Unconstrained Optimization and Nonlinear Equations,equality constrained optimization, SIAM J. Optim. , 7, 28.R. , Practical Methods of Optimization, Wiley, New York, 436

Barhen, J.

2008-01-01T23:59:59.000Z